Computing in Civil and Building Engineering (2014)

This paper reports on some of the activities of a larger study whose overall objective is to propose an optimized configuration for the infrastructure of a BIM-based design coordination room. A methodology for capturing and analyzing the communication pattern among project participants inside a coordination room is presented. Understanding which participant actions ordinarily occur during design coordination meetings is necessary for providing adequate infrastructure support for them. Accordingly, twenty paper-based design coordination meetings were analyzed. Results indicated that text creation (note taking) and floor plan visualization are the most frequent actions by the most usual meeting participants (coordinator, architect and owner). By mapping users' needs to device capabilities, it can be concluded that a large display device, such as an interactive projection screen, may support the majority of actions required from the infrastructure of a coordination meeting room.

A BIM content library organizes Building Object Models (BOMs) in a structured way for easy access, exploration, management, search and visualization. It could be a comprehensive library to cover everything in the construction industry or a corporate website that just hosts models of one single manufacturer's products. This paper proposed an approach of using social involvement to improve the performance of BIM content libraries. Four major problems of existing libraries were discussed:(1) lack of content; (2) difficulty of assessing model quality; (3) no commercial data; and, (4) no support to customized libraries. Proposed social involvement approaches include user upload, BOM marketplace, social rating/comment/vote, manufacturer-specific database, cloud storage, and social tags. This paper presents a framework of using social involvement, and a prototype application is required as the future work for the purpose of validation.

Lack of interoperability has been criticized as an impediment to improving productivity in the Architecture, Engineering and Construction (AEC) industry. For example, the current information exchange between building design and energy analysis models has numerous issues, including object parametric information deficiencies, geometric misrepresentations and re-input data confusion. As a result, it leads to huge money, time and effort losses in practice. The objective of this paper is to present an automated solution for the seamless information exchange between building design and energy analysis models. In order to achieve this objective, a file converter is designed. The file format converter is built upon existing open standards (gbXML and DOE-2 input files) which facilitate the exchange of building design and energy analysis information. Designers could use the converter to properly analyze building energy efficiency for their design models. Also, the design models could be automatically updated if any modifications have been made in the corresponding energy analysis models. The converter has been implemented with Microsoft Visual C# Studio 2013 and its effectiveness has been tested with two popular design and energy analysis tools - Autodesk®-based products and eQUEST®. In addition, the creation of a software plug-in component has also been proposed in order to execute the file converter application. The results have demonstrated the overall rectification of the geometric and material misrepresentations resulting from the current software interoperability process.

A significant challenge in building information modeling (BIM) concerns support for modeling multiple views of buildings to meet diverse data needs of architectural, structural, or building services domains. The focus in this paper is on extending an existing schema for network-based space layouts with spatial composition modeling capabilities. The schema has been introduced in previous work to support modeling of multiple space views. Network-based space layouts are generated from space data that are created in BIM authoring systems. Selected, view-specific, spatial relations between objects in a layout are modeled as a spatial relation network. An architectural designer may use graph algorithms to find the shortest path in the spatial relation network of a pedestrian circulation layout between a workplace and a building exit. Likewise, a lighting control system designer may query a spatial relation network of a lighting layout to determine luminaires that are near a workplace. Multi-view space models may be composed of layouts with view-specific spatial relation networks. However, spatial compositions are currently not modeled explicitly. The schema is, therefore, extended with topological spatial relations which include:containment, overlap, equality, touch, and disjoint relations. With these relations, it is feasible to relate objects in different layouts. They are derived from object geometries with clash classification functions that are provided by a commercial solid modeling engine. Examples from pedestrian circulation and lighting domains illustrate rich spatial composition of network-based space layouts and their benefits for building design.

The emergence of formal BIM-specialist roles was one of the earliest and more obvious changes to industry practice resulting from the introduction of BIM; but, literature suggests that the scope of tasks and responsibilities within such a role remains poorly defined. Following the lead of earlier international guides and handbooks, the recently developed New Zealand BIM Handbook provides a definition of the key roles required for successful BIM implementation in a project. A set of minimum responsibilities is prescribed for project, discipline and technical elements of each BIM-specialist role. This handbook, however, is now being introduced into an industry in which BIM practice has been evolving over several years in a far less structured manner. In order to identify current practice within such roles, New Zealand BIM specialists across a range of disciplines were interviewed. The resulting analysis examines the prescribed roles and responsibilities as set out in the Handbook in the light of existing practice. The discussion encompasses skill sets, role development, reporting and accountability, and the background and training of specialists. Differences in practice between disciplines are identified, and wider concerns over the career trajectory of the BIM specialist are discussed.

Building information modeling (BIM) aims to facilitate information management and collaboration among stakeholders in different domains over the building life cycle. BIM models are increasingly used as an object-based information hub for storing, integrating and managing building information in different aspects. Over the building life cycle, stakeholders - like the owner, designers and subcontractors - keep reviewing and commenting on different building components; but, these social interactions are often not recorded and managed in a structured manner. This paper presents a distributed cloud-based BIM framework that was designed to support collaboration among project participants and information sharing. The framework - namely, BIMCloud - was developed based on Apache Cassandra, which can be deployed on public cloud servers like Amazon EC2 or private cloud servers hosted in their own infrastructures. A schematic data structure was also developed to capture the building component-based social interactions which could be used for mining and post-processing to generate knowledge in the future. The BIMCloud framework stores BIM models based on the IFC schema and the developed schema for Social BIM. Therefore, people can make changes to the BIM models in the BIMCloud framework by transferring only a partial BIM model. An example scenario is presented in this paper.

The character of building design offices has changed dramatically following the widespread adoption of digital design, drawing and modelling. Simultaneously, there is a growing recognition that designers have a responsibility to produce designs with minimal hazards to constructors and operators of facilities. By revisiting the philosophy of engineering, science and design, the radical impact the digital world has upon the traditional working practices of consulting engineering is explored. Consideration is given to the consequences of these changes upon the training, knowledge acquisition and effectiveness of engineers to deliver hazard-free designs. Historically, engineers used approximations and rules of thumb to produce acceptable, if not optimum, designs. Hand calculations undertaken by engineers accorded them the ability to develop a `feel' for the structure allowing `rogue' results to be challenged and corrected. Digital designs are produced so rapidly that the ability to gain experience can be severely impacted, contributing to a blind acceptance of results. Combined with isolated working, minimal scope for collaboration exists, leading to a sense of omniscience. The potential reduction in experiences of engineers raises questions about their ability to understand digital images and the ability to discern the pertinent issues. This paper outlines work being undertaken which could potentially help in the development of digital design systems - including Building Information Modelling (BIM) tools - that could educate and disseminate design for safety (DfS) knowledge, both tacit and codified, which is currently in danger of being lost.

Building information models (BIMs) promise to support information provisioning over the entire lifecycle of infrastructure assets. Currently, however, few integrated BIM decision support systems exist. Therefore, many modeling efforts are being undertaken across the world to gradually support more and more key processes through the application of BIMs. The safety assessment of infrastructure is a key process that can potentially be effectively supported by applying integrated BIM tools. For the Netherlands highways agency, the safety assessment of road tunnels provides an important challenge. Many technical complexities and domain-specific laws and regulations impact safety assessment. Safety assessment is determinative for success; for example, every road tunnel must be checked for compliance with laws and regulations before it can open. This paper proposes an information model that can support the safety assessment task in the context of the Netherlands highway agency. It departs from requirement analysis efforts conducted within the organization and provides use cases and a description of the information model developed. The paper concludes with a description on how we plan to integrate and test the model on the ability to support tunnel projects.

With the growing use of Building Information Modeling (BIM) for vertical building projects, the use of BIM in infrastructure projects steadily increases. Construction companies that build infrastructure facilities are expecting the adoption of BIM since they have observed high return on investment (ROI) resulting from BIM for vertical building projects. In this paper, the focus is placed on the utilization of BIM for quality management in highway and bridge construction. A review of the literature on quality information model and quality control process is presented. The application of BIM for quality management is described. The results of a pilot study by the authors on the model-driven approach to quality assurance (QA) and quality control (QC) is reviewed. Finally, the issues and obstacles to BIM implementation in the infrastructure sector are discussed. Discussions in this paper are on the critical aspects of the utilization of BIM for quality management in infrastructure construction project. Based on the results of this study, great potential has been identified in the use of BIM for quality management in infrastructure projects. Nonetheless, only a limited amount of literature on this topic is currently available. It is believed that this study will set a stepping stone to future research and practice for promoting BIM technology in horizontal construction projects.

Adopters of BIM need to find the most appropriate implementation strategy that is economically efficient for their organization in order to achieve satisfactory organizational and project outcomes. This paper explores why and how the distribution of effort spent on various project activities over a project's life cycle can be used at both project and organizational levels as one of the metrics for evaluating, benchmarking and improving the performance of BIM implementation process. Using a case study, it explores how project time accounting data can be used to visualize and analyze effort distribution pattern. The findings shows the benefit of BIM effort distribution. Based on the visualization, unusual distribution of efforts can be identified and organizations can understand the productivity of their processes. The unusual effort distribution alert can support root-cause analysis process to identify and correct the root causes. On that basis, corrective and preventive actions can be implemented, and BIM process can be improved. The analysis of effort distribution can also help organizations compare BIM projects with non-BIM projects. It can be used to manage cash flow, structure fees, and support return on investment analysis. Effort distribution analysis can increase project participants' understanding of project dynamics from a resource allocation perspective.

The mapping of real-world objects to 3D geometry is of particular importance for engineering applications such as as-built modeling for progress monitoring and energy performance simulation. The state-of-the-art methods for fitting NURBS to point clouds still fail to account for all the topological variations or struggle with the mapping of physical space to parameter space given unordered, incomplete, and noisy point clouds. To address these limitations, we present a new method which starts by successively fitting uniform B-spline curves in 2D as planar, cross-sectional cuts on the surface. An intermediate B-Spline surface is then computed by globally optimizing the cross sections and lofting over the cross sections. This surface is used to parameterize the points and perform final refinement to a NURBS surface. Assuming an input of points that can be described by a single, non-self-intersecting NURBS surface, the algorithm outputs a NURBS surface. Experimental results on several real-world point clouds show the applicability of the proposed method for as-built modeling of civil infrastructure systems.

Building Information Modeling (BIM) technologies and processes enable different implementation levels or use stages with varying degree of integration (e.g. file-based collaboration, model-based collaboration). While there is no general agreement on the terminology to denote such levels or use stages, file-based collaboration and model-based collaboration - often called also integrated BIM - are the two levels being investigated in both academic research and industry applications. In file-based collaboration, project participants from a supply chain produce federated BIM models that are merged together for specialized purposes (e.g. design coordination) only at specific project lifecycle phases. In model-based collaboration, all participants work on a synchronized central model that is integrated and can be shared among them at project phase. Model-based collaboration represents a significant paradigm shift in industry practices. In recent years, much of the research in both BIM technologies and processes has been focused on BIM file-based collaboration. This research proposes a low cost IT platform that enables BIM model-based collaboration and a real world case study. The proposed platform and benefits and the challenges from working in this environment are discussed in this paper.

This paper conceptualizes a framework for bridging the BIM-Specifications divide by embedding project-specific information in BIM objects by means of a product library. We demonstrate how model information, enriched with data at various levels of development (LODs), can evolve simultaneously with design and construction using a window object embedded in a wall as lifecycle phase exemplars at different levels of granularity. The conceptual approach is informed by the need for exploring an approach that takes cognisance of the limitations of current modelling tools in enhancing the information content of BIM models. Therefore, this work attempts to answer the question, "How can the modelling of building information be enhanced throughout the lifecycle phases of buildings utilising building specification information?"

This study investigates a novel approach - both to precisely plan for project execution and to monitor execution status in near real-time. In this approach, two lean construction techniques - such as pull planning and integrated project delivery - are combined with the fine-grained planning and near real-time monitoring of the executed work. In order to plan for and monitor the flow of work, work packages are defined at the smallest discernible amount of work - the task. Work packages are divided by unique location sectors and, hence, are further discretized. Deviations based on predictions of completed work are proactively reported and assessed in near real-time. In addition, productivity ratios for completed projects are utilized to pre-qualify contractors for future project endeavors and to generate accurate bidding information. Thus, an emphasis to stabilize workflow is at the core of the proposed fine-grained production planning and near real-time monitoring approach. Through an intervention test in a facility project, a comparison of relevant metrics is used to quantify and validate the impact of the novel approach.

Over the past few years, anecdotal evidence and controlled studies on predicting the actual energy performance of existing buildings have raised concerns about the accuracy of energy performance simulations using Building Information Models (BIM). Among numerous sources of modeling inaccuracy, the wrong thermal properties of solid assemblies can significantly impact the reliability of the BIM-based energy analysis. Without considering the diminishing thermal resistance (i.e., R-value) of building materials caused by their deterioration and updating such material properties in BIM, BIM-based energy simulation of existing buildings could be unreliable for retrofit decision-making purposes. This paper proposes an automated method for updating the R-value of building elements in BIM. By exploring 3D spatio-thermal models reconstructed from 2D thermal images, the actual R-values are calculated at the level of 3D points. The calculated actual R-values are used to automatically update the thermal properties of the corresponding gbXML-based BIM elements. For validation, several experiments on measuring and updating the R-value of BIM elements are conducted in an existing residential building. Using the proposed method, BIM-based energy analysis tool scan more accurately model the as-is conditions of existing buildings and estimate their actual energy performances.

As hazardous situations occur in public spaces, decision making for rescue is always the most important but challenging task. Nowadays, this issue has lead to the necessity of computer-aided approaches. This research considers the fire situation in public spaces, and the rescue plan is influenced by various attributes, such as: (1) geometry and material of building elements; (2) the spread of fire and smoke; and (3) the behavior of endangered people; and (4) escape routes. The authors combined network analysis with Building Information Model (BIM) to facilitate the decision making for rescue operations. Building geometry is retrieved efficiently from BIM for network generation and route finding, and material properties are acquired for fire risk analysis by using the Revit Application Program Interface (API). Rescue routes based on graph networks for rescuers can be calculated depending on actual building conditions. Risks based on building materials are expected to be adapted into network edge costs for lowest risk route finding. It is expected that the accuracy and efficiency will be greatly improved for decision making in in-building rescue operations.

This paper describes the research and development of the Dutch national standard for information levels of BIM. The US-developed "Levels of Development" (LOD) have become increasingly popular in the Netherlands. However, more and more projects felt the need to develop an additional LOD250 and LDO350. It became clear that the Dutch design-and-engineering process needed different information levels to operate effectively. During an R&D project that involved 9 Dutch SME companies research was done focused on the levels needed in the Dutch AEC industry. During this project, the team also looked at several other information levels - the Danish, the Australian, and the UK RIBA information and the LOD concept in CityGML. The project team came up with 7 information levels. A matrix was developed on which construction objects were linked to the 7 levels. Several companies in different BIM projects tested this matrix in practice. Results from this test were concluded in a guideline for effective use of the information levels and the matrix. This paper will describe the test results and the resulting recommendations for practical use of the standard in the Netherlands. Furthermore, an experiment was conducted to automatically identify the detail of the geometry of an IFC model. This was done by analyzing several characteristics like number of objects per m³, and number of geometrical triangles per object. The results of this geometrical test are also added in the paper.

The article considers some of software complexes for building master plan visualization as a whole and its components. Special focus is on possibility of increasing quality of design performance and wider number of technically unskilled users.

The growth and advantage of Building Information Modeling (BIM) has recently gained momentum in the expanding needs of the construction industry, one that varies across disciplines. The UK government is the largest public stakeholder client that has realized the benefits and advantages of BIM when used in procuring projects. The usage and adoption of BIM in all UK government-procured projects with a Level 2 BIM status will be mandatory by 2016. Will this target be achievable by 2016? This study investigates that possibility. A critical review of the BIM literature and the evidence based on the government target of 2016 was carried out. At the current stage, it appears that Level 2 adoption is achievable by 2016 for large construction firms. However, the technology needs to be properly tailored to meet SMEs variables if the Level 2 status is to be achieved for the entire industry.

Construction projects have become very complex - comprising varying activities and processes, and requiring inputs from a wide range of disciplines, especially in the adoption of Building Information Modelling (BIM) technologies. Dealing with such matters has raised several issues, such as data inconsistency, different data versions, and data loss. Even though BIM offers a means of solving such problems, evidence suggests that a governance model is needed to facilitate BIM management across the construction project supply-chain and lifecycle. A comprehensive survey was conducted with the aim of identifying construction industry practitioners' requirements for developing a non-proprietary BIM governance model for facilitating collaboration throughout the supply-chain during a building's lifecycle. Informed construction practitioners in the UK were the main contributors to this study. The findings of the survey reveal the need for a non-proprietary BIM governance model with its underpinning cloud infrastructure storage solution for facilitating collaboration across the supply-chain during a building lifecycle. This study seeks to lay the foundation for such a model.

Building information modeling (BIM) is a process that has the potential to positively impact the performance of architecture, engineering, and construction (AEC) projects. Previous studies showed the quantitative performance benefits of BIM from a general perspective. This paper aims to build upon the previous studies and investigate the effect of BIM Uses on a specific key project performance metric: project change. BIM Uses include visualization, clash detection, code checking, early coordination between stakeholders, and others. The research methodology includes conducting a principal component analysis (PCA) on a dataset of 34 completed vertical construction projects. A new input, the BIM Use Score, was created through PCA and was used to test if increased BIM Use actually affects project change metrics. Interesting results emerged from the analysis, including: (1) the lack of relationship between BIM Use and the extent of project change, and (2) a potential correlation between BIM Use and the project change initiators. Increased BIM Use seems to result in less design changes but more owner changes. The findings of this study provide a more comprehensive understanding of the impact BIM Use can (or cannot) have on project performance, ultimately helping project stakeholders decide how to most effectively use BIM on their projects.

Building Information Modelling (BIM) is one of the most visible aspects of a deep and fundamental change that is rapidly transforming the global construction industry. It is the platform that brings about collaboration between project stakeholders and improvement of project outcomes. The growing worldwide adoption and implementation of BIM for its powerful data-based modeling, visualization, analysis and simulation capabilities represents a paradigm shift to an integrated digital information infrastructure that will ultimately revolutionize almost all aspects of the construction industry. Many developed economies of the world have recorded impressive outcomes by implementing BIM in their construction practices, and this necessitates the need for an investigation into the level of its awareness and factors affecting its adoption in the Nigerian Construction Industry. The study was undertaken through a survey of Nigerian Building construction firms. The central issues addressed were the awareness of the respondents on BIM, and their perception on the drivers and barriers to its adoption in the Nigerian construction industry. Structured questionnaires and semi-formal interviews were used for data collection. The study highlighted areas requiring attention by researchers, government and other stakeholders towards a country-wide implementation of BIM technologies and hasset a scene for developing a framework for BIM adoption in the Nigerian construction industry. This will make the industry equipped to: (1) operate in line with the global best practices; (2) deliver projects successfully and more efficiently; and,(3) be a good market from which foreign firms will benefit.

The construction sector of Luxembourg is a particular trans-national market where companies, methods, regulations and equipment are largely influenced by France, Germany and Belgium practices. As in other countries, IT seems to play a major role in sectorial innovation as a means for improving competitiveness of companies and efficiency of projects delivery. There is a need for understanding the maturity of the sector regarding IT for several reasons. First, the sectorial push towards innovation from public incentives and private bodies targets the areas of project management and competitiveness of companies relying on IT. Second, a nationally standardized, web-based project platform (CRTI-weB) is emerging and used in several projects. However, resistance is observed and is possibly caused by heterogeneous IT competencies of users. Third, BIM is gaining interest in the sector although the adoption rate remains very low. BIM seems not understood by construction practitioners as enabling new collaborative practices. On the basis of these considerations, the paper describes the setup of the IT Barometer survey for Luxembourg. The aim of the survey conducted is to provide a robust analysis of the as-is situation of the sector regarding IT. Although the survey is still in progress, the authors provide first evidences enabling to understand the conditions in which the nationally established CRTI-weB is being adopted as well as developing requirements for the development of a BIM implementation roadmap for Luxembourg.

The research aims to perform an analytical study of actual variations in construction contracts in Jordan through recognizing the types of variations which occur in the contracts, and reasons which affect those variations. In order to realize the research purpose, the related data were gained from the sources of all sides of the contract (clients, consultants, and contractors) through: (1) several interviews; (2) historical data of pre-executed contracts; and (3) a questionnaire form distributed to the three parties. The results of analyzing historical data (640 cases of variations occurring in 58 contracts) showed that, of the variation in quantities within the ratio:(1) 20% of the work was of the most common types of variations occurring in contracts, as they reached more than 40% of the total variations (studied); and (2) they were followed by other types of variations (i.e., variations in quantities more than 20%, additions, quality variations, and deletions). The results of the same matters from the questionnaire showed the same sequence but slightly different figures. In addition, the study showed that the three parties (clients, consultants, and contractors) share almost equal responsibility for the reasons for the occurrence of variations. Reasons beyond the control of these parties received less attention.

Going "green" and global has marshaled Architects, Engineers and Contractors (AEC) to use Building Information Modeling (BIM) to be competitive across the globe. However, little is known on the effect of cultural and human factors on BIM technologies in industrialized building projects, especially in Malaysia. This paper examines the extant literature of BIM technologies to reduce construction waste and improve the efficiency of Industrialized Building Systems (IBS) in the fabrication process. The paper supports BIM's implementation as AEC professionals' communication culture, effective cultural knowledge to mitigate knowledge loss, and key enabler for fabrication in a project. The paper concludes that, despite having competent technological support, fabrication efficiency is still much affected by cultural knowledge between professionals during the design phase which could affect production of waste in IBS construction. The result is expected to improve AEC collaboration knowledge during sustainable development through efficient environmental management during an industrialized project lifecycle.

A recent report by the National Research Council of the National Academies (NRC) has defined the research on understanding and quantifying the environmental, social, and economic value of our infrastructure systems to their stakeholders as a "national imperative". There is still a lack of understanding and of formalized modeling of what different stakeholders value (e.g., energy conservation) in our infrastructure systems and how to valuate (i.e. quantify the worth of) our infrastructure systems based on these values. In our previous work, we conducted theoretical and empirical studies to identify what different stakeholders value in educational buildings. In this paper, we focus on presenting our value quantification model - our model for quantifying the worth of an educational building based on different stakeholder values. We also present our methodology for selecting the indicators that will be used for value quantification. The paper also discusses our approach of integrating our valuation model with Building Information Modeling (BIM) so that we can automatically extract the data needed for valuation from an existing BIM project model. We conclude the paper with a case study.

With the development of Building Information Modeling (BIM) technology, there has been an increased application of BIM-based modeling and energy analysis tools in building design. Although there are several popular energy analysis tools available, there is currently no effective way for users to verify the accuracy and reliability of their results and to compare the differences between different analysis tools. Therefore, the Computer-Aided Engineering Group at the Department of Civil Engineering, National Taiwan University is developing a test bed for researchers and practitioners to share verification data - with both the BIM model of a test-case building and the actual measurement data of the energy performance of the building - which can be used for verification and comparison of various building energy analysis tools. This paper discusses the design and implementation of the test bed. The test bed consists of three major parts: (1) the repository of the BIM model of the test-case building with measured energy data; (2) user interfaces for users to upload and retrieve test-case information and model data in an organized and convenient way; and (3) utilities for users to convert data between different formats used by different energy analysis tools and to evaluate the energy analysis tools based on comparisons of analysis results with actual measurement data.

With the contemporary improvements in construction IT, the use of building information modelling (BIM) has become a considered approach in construction transactions. This places demand on BIM to become fully matured and all-encompassing with respect to operations of various professional platforms and the performance measure of artefacts. Sustainability is one such measure associated with buildings. For the structural engineer, recent design criteria have put great emphasis on the sustainability credentials as part of the traditional criteria of structural integrity, constructability and cost. As such, a means for assessing the sustainability credentials of design solutions to guide early design decisions has become a necessity. There exists decision-support tools to aid sustainability assessment of buildings; however, these tools will be more beneficial when built into the design solution from its inception. This paper highlights existing deficiencies and examines how contemporary modelling techniques can be employed to tackle identified gaps. The work proposes a prototype system for appraising the sustainability of design options at the conceptual design stage. The system is based on a framework which uses life cycle costing as a measure of accounting for economic sustainability and a combined carbon and ecological footprint for the environment. It is implemented in C# using .NET Frameworks and Revit API. This paper demonstrates that the utilized information modeling representations - in the form of a process model, implementation algorithms and object-based instantiations - can capture sustainability-related information to inform decisions at the early stages of the structural design process.

Recent advances in Building Information Modeling (BIM) and the emergence of mandatory building energy codes and specifications encouraged the integration of energy performance rating and energy analysis and simulation in building design and operation. Building Energy Performance (BEP) ratings and simulations and the Architecture, Engineering and Construction/Facility Management (AEC/FM) disciplines are converging. However, current BIM databases contain data that support, mainly, AEC/FM tasks. Few attempts have been made to include data that support BEP rating and simulation. In this study, a conceptual framework for a Building Energy Model (BEM) that captures the data needed for building energy performance rating and simulation has been presented. A case study, using a warehouse, is used as a test-bed for proof of concept and for validation of the developed framework. The ultimate goal is to develop a data model that supports the integration of BEP rating and simulation to facilitate building design and operation.

Value Engineering (VE), as used in building design and construction projects, aims to identify opportunities to reduce construction cost, optimize the performance of the future building, reduce future operating expenses and cost, shorten building delivery time, and possibly avoid (future) legal problems and litigation. In its current practice, VE action typically focuses on issues for which quantitative data are on hand (i.e. reduction of construction cost based on cost estimates), while leaving to speculation the assessment of the impact of a given construction cost reduction on the future building's performance. Most new building designs include features and measures to minimize energy consumption; but, once in use, such buildings often fail to meet their energy performance expectations. Analyses of design histories usually show that the planned and designed energy efficiency features and measures were eliminated due to blunt cost cutting in VE events. This paper describes Performance Based Value Engineering (PBVE), which can mitigate problems encountered in standard VE events. It employs semi-automatic generation of input for simulation of building energy performance, which enables quick delivery of predicted energy performance and operating cost to provide a quantitative counter argument to blunt cost cutting.

Building Information Modeling (BIM) within the design and construction industries has grown in popularity, complexity and usefulness. Most large firms have adopted it to some degree. BIM use for facility management by the owner, however, is lagging. This research examines the usefulness of BIM beyond construction and into facility management and operations. A survey was used to establish industry use of virtual modeling and BIM and was followed by the development of a series of case studies that focused on professionals that have implemented BIM beyond construction. The developed case studies verify that construction firms are faced with challenges when they need to turn over the model to facility owners. This study identifies the keys to successful post-construction BIM utilization and how it can be supported by the contractor. This research aims to bridge the gap between the contractor and owner. It will result in the development of a framework to aid contractors in the process of turning over the BIM to the owner for post-construction activities. This paper discusses the proposed framework and research methodology as well as the initial observations resulting from the case study development. The benefits of this type of system, as well as the major obstacles in its creation, are also discussed.

There has been considerable and well-documented concern about the current state of public infrastructure - roads, bridges, water and waste systems, etc. The causes of these challenges - (1) aging and deteriorating infrastructure; (2) inadequate funding; (3) competing organizational objectives; (4) questionable maintenance, repair, rehabilitation and replacement practices in the past; (5) demographic and population shifts; and (6) new understandings about sustainability objectives - are common to many government and utility owners. These challenges necessitate that the infrastructure industry excel at developing and managing its infrastructure systems to their maximum potential. To meet these needs, the infrastructure domain requires improvements to the decision support tools that currently exist for sustainable infrastructure management. This paper reviews this problem with a particular focus on the Canadian context, and outlines a course of action to address the current needs. The proposal addresses three domains in the field of sustainable infrastructure management. First, it builds on work to develop comprehensive techniques to assess the sustainability of infrastructure systems. Second, it attempts to advance multi-objective optimization techniques and tools for predicting the long-term performance of infrastructure systems and optimal strategies under a variety of maintenance regime alternatives. Third, it develops data interoperability solutions to create an infrastructure data integrator as a computing platform for this work.

Advanced Energy Retrofit (AER) projects can significantly reduce energy consumption of existing buildings, and studies have indicated that they can be more economic than constructing new buildings. Retrofit projects vary in complexity based on the building characteristics, building area, client requirements, project budget, payback period and energy savings targets. The lack of a transparent and streamlined integrative process makes it difficult for the participants to implement AER projects. To implement comprehensive AER projects (also known as Deep Retrofits) in an efficient manner, it is important to understand the process along with the information exchanged during the planning, design, construction and operation phases. This paper describes the development of an AER integrative delivery process model with a focus on the planning and design phases. The integrative process has been developed through a detailed literature review, and studying the project documents and procedures used to deliver an ongoing comprehensive AER project. It was validated by review in multiple industry workshops and through interview with industry and academic experts, including all the primary team members of a comprehensive AER case study. The process is undergoing additional validation through AER integrative workshops and a detailed case study analysis. The final integrative process includes activities focused upon specific building systems along with integrated processes and information exchanges which support the integrated workflow among team members. The identified important information exchanges outline a series of exchanges that support application interoperability for AER projects.

The goals of fire protection activities are to prevent fires, rescue people and ensure the effectiveness of firefighting. To achieve these goals for complex buildings, holistic fire protection concepts are developed which should take into account the special characteristics of each building. To ensure fire safety during the building lifecycle, a maintenance strategy is required. This includes recurring site inspections by experts, especially when a building needs to be refurbished or in the context of a technical due diligence during real estate transactions. If a malfunction of a fire safety element is detected in the context of these inspections, this is called a fire protection deficiency. These deficiencies decrease the fire safety rating of the building, increase the risk level, and result in deferred maintenance costs. For the analysis of the fire risk level and for risk comparisons between buildings and fire protection concepts, different techniques and approaches are available and are summarized under the term risk methods. A problem during this process is that findings and results from risk assessments are difficult to bring together with the real building. Information of the influence of individual fire safety deficiencies (technical, structural fire protection elements/components) on the risk level of the whole building and the associated repair and replacement costs are not directly related. This relationship must be associated in the expert's mind based on different documents. To overcome these limitations and to support the planning of deferred maintenance tasks, the goal of the presented approach is to visualize all required information within a BIM environment.

Nearly 80% of green certified structures in Australia are commercial office buildings. Attaining the highest certification often requires the application of design modelling and analysis tools, demanding greater levels of design coordination and management. Whilst the opportunities for green building certification to benefit from building information modelling (BIM) may be obvious, in Australia, the relationship is yet to be validated. This research seeks to address this gap by evaluating the application of BIM for green building certification. The authors present a case study of an Australian commercial office building. Project participants were interviewed and the as-built BIM model audited to analyse data against certification criteria. The results identify gaps in design management and modelling practices, as well as a lack of alignment between design activities and green building certification criteria. Gaps in internal project coordination were more pronounced than with external certification tasks. The study suggests the development of dedicated BIM execution and coordination plans for green building design and certification is required, and discusses the mapping of BIM management requirements with certification standards, criteria and processes.

The construction industry is turning more and more towards sustainability. To achieve sustainability, a balance between environmental, economic and social aspects has to be reached. Therefore, these criteria have to be taken into account during the building design phases. LCA is a suitable tool for assessing a building's environmental performance. Nevertheless, it has some issues that need to be resolved for its integration in the design process and use as an assessing design tool. By integrating LCA with other tools, such as BIM, a more holistic approach to sustainable construction could be achieved. Thus, tools which are already existing can create synergies for attaining higher efficiency and sustainable construction. Furthermore, these tools should be implemented from the early project phases onwards, since the capacity to influence the project is greater in these phases. Finally, two different approaches for integrating LCA and BIM are presented in order to highlight future research fields.

In the course of the research project, a prototype system has been developed at the Institute of Construction Management in the University of Kassel, Germany. The developed system performs its task in two phases:(1) Building Information Modeling (BIM)-based generation of a 3D-site layout plan and (2) a simulation-based evaluation of the site layout plan. BIM-based generation of the site layout plan takes place within a BIM environment based on an optimization methodology for automated dimensioning and locating of the site facilities. This methodology depends on geometry data of the building and obstacles at the site. It also depends on the equipment which is available for the project, the number of staff, the construction methods to be used, as well as the necessary safety measures at the site. For the sake of the generation process, a 3D-parametric library has been developed; the elements of which are used as basic components for the site layout plan. The degree of utilization of the site equipment is determined in the "simulation-based evaluation of the site layout plan" phase. For this phase, an agent-based simulation model has been developed. This model is capable of simulating the behavior of all elements on the site and the interaction between them and their environment. The required data for the simulation is read from the BIM environment and input via the built-in and self-developed user interface within the BIM environment. This paper describes the site layout planning problem and the previous efforts to solve it by using computers. It also illustrates the necessity for effective site layout planning system and clarifies the system architecture which is developed for this purpose.

This research explores scheduling purposes and related 4D-CAD requirements during planning and realization of a 900-m sewer line construction project. We used an ethnographic-action research approach to investigate how changing scheduling purposes influence 4D-model setup. To this end, we implemented 4D-CAD in a real-life setting, iteratively improved the model, and observed how it was used by practitioners. Observations showed that,in the planning stage, scheduling concentrates on task identification, resource allocation and stakeholder communication, while jobsite scheduling focuses more on operational task dependencies, delay mitigation and site logistics. These changed purposes eventually impact required detail and focus of 4D-CAD models.

Sixty-five percent (65%) of US workers in the construction industry work on scaffolding. Of these workers 4,500 are injured and 50 die every year due to scaffold-related accidents. Proper safety management, such as scaffolding safety inspections, can support hazard mitigation and prevention. This paper shares the results of a study of the levels of safety risk at each stage of the scaffolding project life cycle for building a masonry wall and how these risks and related mitigation suggestions can be applied to Building Information Models (BIM). Safety is integrated with 4-dimensional (4D) BIM by linking the scaffolding safety risks and mitigations with the project schedule. The 4D BIM can be used as a tool for the safety management to monitor and diminish the safety hazards associated with scaffolding work. Four different stages of research were conducted to determine the safety risks and then implement the mitigations into BIM: (1) Determine the activities associated with working on scaffolding; (2) Collect data from industry professionals about the likelihood and severity of safety hazards at each stage of the scaffolding project life cycle; (3) Establish the safety risks using the collected data and a standardized algorithm; and (4) Incorporate the safety risks into BIM and provide mitigation recommendations. As a result, the 4D BIM can be used throughout the project planning and construction progress to inform the safety management of activities associated with the scaffolding that have high safety risks and to assist safety management in implementing preventative measures according to given mitigation recommendations.

Visualization of construction schedules has much improved through the development of 4D modeling tools that offer an effective method for schedule planning and management. While increasingly used by the construction industry, existing 4D tools are being continually improved. Many new tools are being developed, especially with the increased adoption of building information modeling (BIM). The ability to observe the animated sequence of the construction process and track the construction status of each building component is just one of many possibilities offered by 4D modeling applications. However, as with the proliferation of any new technology, one of the inherent challenges with 4D modeling tools is a lack of agreed-upon visualization standards for representing building elements and tasks. Specifically, each tool typically has its own standards for viewing and navigating the model and schedule. Interviews with AEC professionals and experts provide insights from the end-user perspective of the current visualization methods along with their recommendations. To start addressing some of these challenges, our team reviewed the current status and methods for visualizing construction schedules, building on the research efforts in the domains of information visualization and human-computer interaction. Based on the current experiences and feedback from AEC industry practitioners, a set of visualization guidelines for representing the construction process was developed which supports future efforts in 4D model use and development.

Temporary structures, like scaffolding, have a significant impact on the quality, safety and profitability of construction projects. Workplace Health and Safety (WHS) Authorities in Australia have found that 40% of all scaffolding projects do not comply with national safety and design standards. Thereby, the practical guidance in scaffolding cases should be treated as a critical research focal point in conjunction with the general Australia-wide Occupational Safety and Health (OSH) requirements, acts and regulations. At present, limited research attention has been placed on the impact of design and validation of scaffolding erection and dismantling on OSH, especially considering working at height. To address this issue, the aim of this paper is to: (1) develop a framework of mathematical optimization algorithms for scheming the scaffolding erection and dismantling during the planning process, and (2) explore how to combine the mathematical methods to produce a good solution in a relatively short time by taking consideration of special characteristics and complications of scaffolding. The framework can resolve the relatively multi-objective optimization issues and produce the optimal solutions with higher complexity. In parallel, virtual simulation scenario to digitalize the optimized work schemes of scaffolding is also proposed within the framework. In this sense, several sources of risks in scaffolding erection and dismantling - including: (1) work area design and lay-out (e.g., inadequate space for task type); (2) the nature of equipment or tool; and (3) erection and dismantling sequences load and working environment - will be comprehensively optimized and visually simulated. It is envisaged that this integrated framework that combines the mathematical algorithms and virtual representation might, for the first time, automate the most effective way of controlling the risks in the context of scaffolding practice.

This paper presents a generalized, flexible and formal framework for representing various requirements to support the needs of the construction process using the Industry Foundation Classes (IFC) model specification. These are termed construction requirements. The importance of considering construction requirements as a representation of construction knowledge within the context of construction planning and scheduling will be discussed, allowing readers to gain an understanding of the applicability of construction requirements. An ontological model for describing these construction requirements will be proposed in this paper, which will aid in formulating a uniform representation schema for construction requirements. This model will define the attributes of the construction requirements ontology from the perspectives of spatial, temporal and ordinal characteristics. From these attributes, various construction requirements may be represented as construction requirement entities. These construction requirement entities demonstrate how the functional and non-functional characteristics of a building element system may be captured for constructability analysis. This paper concludes by explaining how the construction requirements may be extended to represent construction methods, and underlines its applicability to automated constructability analysis, as well as automatic schedule generation.

Assembly Bill 758 (AB758) of the California Energy Commission (CEC) incentivizes radical improvement of energy performance in existing buildings. Execution of AB758 relies heavily on building performance data and energy assessment. Traditionally, building performance data are not available for public consumption, while energy assessment is complex and time-consuming to conduct. Thus, a Virtual Facility Energy Assessment(VFEA) strategic planning tool is proposed built upon the robust integration of Geographic Information Systems (GIS) and Building Information Modeling (BIM) with a cloud infrastructure. For owners with large portfolios of facilities, such as the California State University (CSU) system, VFEA can leverage location-based building information, dynamic simulation capacity of BIM and wireless sensor network (WSN) for real-time building energy performance detection, visualization, analysis and optimization across campuses. It provides stakeholders a dynamic and holistic virtual assessment for energy performance of buildings that are geographically dispersed. VFEA offers conceptual, yet informative, suggestions in the decision-making process directed to meet the AB758 requirements. This paper conducted the feasibility analysis, established the system framework of VFEA, and discussed the use case of CSU, Fresno campus for VFEA implementation.

In the context of interior finishing works, delays to the initially planned schedule occur frequently. Since disturbances are unavoidable, a continuous acquisition of the construction progress is essential. Current practice of acquiring the actual construction progress is performed manually and, therefore, is work-intensive and time-consuming. There are approaches that are based on the acquisition of image and video data to derive the current state of objects. Drywall is a very particular case of detectable objects because the extent of the walls frequently do not fit in the sensor of the camera system. Therefore, it requires image features that allow the distinction of different completion states without the feasibility of the investigation of the whole wall. In this paper, the special case of a drywall completion state determination is examined. A method that deals with the automatic detection of the three states - namely: (1) the installation of panels; (2) plastering; and (3) painting - is presented and they are analyzed. Features are derived that allow for the differentiation of the states and a cascaded classification is performed. Therefore, a test set is created consisting of real image data acquired from the finishing of the interior of a building. A Support Vector Machine is trained with the extracted features, and images are tested against the trained classifiers to demonstrate the success of the method.

Despite the benefits offered by the simulation and visualization of construction processes, this class of technologies has yet to be adopted on a large scale in the industry. Reasons include: (1) the time and effort required for data collection and preparation of Discrete Event Simulation (DES) models and (2) the requirement to consider additional geometric information about the visualized components (e.g. worksite, work product, equipment) in order to correctly and completely visualize the simulated operation. This paper introduces an approach to the simulation and visualization of construction operations that employ robot simulators for the encapsulation of functionality and performance characteristics, and that enable the intelligent execution of programmed work tasks with due consideration of the virtual environment in which they are conducted. Our conceptualization of a robust methodology for the introduction of robots into construction sites through the synergistic combination of two proven technologies, viz. DES and robot simulation, is described. The abstraction of geometric and performance characteristics within a reusable robot model frees the operation modeler from concern over details such as the duration of activities and geometric considerations, thereby greatly decreasing the time andand effort required to produce correct and convincing visualizations of operations which, in turn, could lead to the widespread adoption of these technologies in the industry.

This paper presents a new method for operation-level monitoring of construction progress using image-based 3D point clouds and 4D Building Information Model (BIM). Previous research on comparing point clouds to 4D BIM has proven the practicality of performing progress monitoring by occupancy-based assessment - detecting if BIM elements are present in the scene. Nonetheless, without appearance information, operation-level monitoring - formwork vs. concrete surfaces for concrete placement - is still challenging. By leveraging the interconnectivity of site images and BIM-registered point clouds, this paper presents a new method for densely sampling and extracting 2D patches from all site images from which BIM elements are expected to be visible. Our method reasons about occlusions in the scene and classifies the material in each image patch. By formalizing the sequencing knowledge of construction operations for progress monitoring purposes and using histogram-based representation for possible types of construction materials, our method can accurately detect the current state-of-progress for BIM elements in the presence of occlusions. We introduce a new image dataset for material recognition, and present promising results on operation-level progress monitoring on an actual concrete building construction site. Our method addresses the challenges of working with non-detailed BIM or high-level work breakdown structures.

Operations and Maintenance (O&M) is well known for its interdisciplinary knowledge. Currently, maintenance staff usually refers to original blueprints and as-built drawings - most of which have been rendered useless by decades of upgrades and retrofits - whilst low productivity caused by deficient information transmission between the different departments leads to labour wastage and high cost. Building Information Modelling (BIM), as a powerful approach, is used as 3D information models for maintenance process visualization and coordination. However, the O&M departments are facing barriers and challenges in BIM adoption as there is no clear guidance or best practice studies from which they can learn and build up their capacity for BIM use in order to increase productivity, efficiency and quality. Lean concepts, as new management thinking has suggested, is a better maintenance process by improving the reliability of flows and waste estimation. This paper aims to apply BIM and lean concepts to practical maintenance to improve efficiency. Firstly, the paper starts by discussing and analysing the limitations of existing O&M activities in this regard. Then, an overview of the proposed approach for integrating BIM, lean concepts and maintenance is presented. Finally, a case study is chosen to verify the integrated approach. The result shows that the approach can effectively improve maintenance efficiency.

This paper reports on the first part of ongoing research with the goal of designing a framework and a knowledge-based system for 3D parametric model-based quantity take-off and cost estimation in the Architecture, Engineering and Construction (AEC) industry. The authors have studied and analyzed current cost estimation methods used in both the AEC and non-AEC industries in terms of their requirements, use contexts, methodologies, limitations and strengths to lay the groundwork for selecting the most suitable problem decomposition methods and cost estimation techniques to design a new framework. We have focused on determining the underlying methodologies of different cost estimation models and not just the techniques. Both qualitative methods used in early stages of design and quantitative methods used in more mature design stages are reviewed and their structures are analyzed.

Projects in the Architectural Engineering and Construction (AEC) industry involve several organizations and practitioners who are required to share a very diverse set of information and models. Building Information Modeling (BIM) and open standards, such as Industry Foundation Classes (IFC), have made substantial progress in improving the interoperability in recent years. However, inadequate interoperability is still inflicting an economic burden and is considered to be one of the main limiting factors for BIM adoption. This paper presents an IFC and Web-based approach and tool that enable a bi-directional conversion among structural analysis models. The approach consists of an IFC-based unified information model and a number of algorithms that help overcome the differences between the data structures and representation logics of different structural analysis technologies. A web-based platform that utilizes WebGL was developed to enable the sharing and converting of different building models. In a live case study, the testing of the approach and the platform developed demonstrated consistency in the conversion process and stability and rendering quality in the display of models over the Web browser.

The Architectural, Engineering and Construction (AEC) industry has long strived to assess the likely post-earthquake condition of structures. Recently, the Pacific Earthquake Engineering Research (PEER) Center has developed an appropriate basis for seismic damage assessment, including cost estimation and scheduling for post-earthquake building rehabilitation. However, without proper visualization, these numbers may fail to communicate the actual operability of the building after an earthquake. The proposed methodology relies on the integration of tools currently available to the AEC industry, such as: Building Information Modeling (BIM), a fourth-generation programming language, a relational database management system and construction management tools within the PEER Center framework. This process is automated through the development of appropriate software and is applied to a one-story reinforced concrete moment-frame (RCMF) building, providing the BIM with data about elements' damage state, 3D damage assessment visualizations, the expected rehabilitation cost and duration for different levels of seismic intensity. Hence, engineers and developers have the unique opportunity to create a holistic picture of any RCMF building's seismic behavior which is comprehensible by non-engineer owners, customers and shareholders.

Converting remote sensing point cloud data (PCD) into solid CAD models consisting of civil infrastructure components is a crucial step in generating the as-built building information models. Previous research has enabled automatic generation of surface primitives from raw PCDs. However, the fully automatic conversion from surface primitives to infrastructure component models remains an unsolved problem. In this work, an automatic and linear-runtime approach is presented which generates the as-built infrastructure component models by recognizing the solid CAD entities and learning the infrastructure component labels from the fitted surface primitives. The algorithm utilizes a decision tree with the following decision variables: the type, parametric model, orientation, and mutual geometric relations of the fitted surface primitives. The decision tree is trained with easily generated synthetic data and is applied to query real-world data with complexity O (1). The output of the solid entities includes cuboid, cylinder, and ball, and the infrastructure component labels (such as columns, caps, deck, and beams). The algorithm is tested with various PCDs modeling real bridges.

For the purposes of integrating a solar energy system design into BIM, this study proposes a new design model which deploys solar panels and design evaluation directly into BIM. In the proposed model, the functions of energy analysis software and solar design software are integrated into customized BIM tools developed using Revit and its API. Such integration allows users to perform solar system design for buildings in a BIM environment; further, the design is directly integrated into BIM. The user first uses BIM tools to build a BIM for a building, then the geometric information of BIM is exported to an energy analysis software for radiation analysis on the building envelope. After analysis, BIM tools import and display the analysis results using color contours on BIM. Based on the color contour of BIM, the user can choose optimal locations on the envelope of BIM to install solar panels. Finally, BIM tools can calculate the power generation of current deployment. Since the aforementioned design operations are all performed in a BIM environment, the user can continue revising and re-evaluating the design directly on BIM to reach an optimal design.

A preliminary feasibility study evaluates various aspects of a project, such as environmental assessment, field study, technological validity, and economic feasibility. Among them, economic feasibility is the most important factor to use in selecting a road route in Korea. A proper preliminary feasibility study considers all costs incurred in the life cycle of the project, including construction costs, land acquisition costs, collateral expenses, and operation and maintenance costs. However, only construction costs are traditionally considered in the assessment of the financial viability of national road projects. In addition, while 3D modeling techniques have brought improved designs and engineering processes to the construction industries, their application in preliminary feasibility studies remains rare. We have developed a system that employs building information modeling and geographic information systems for estimating the cost of building a national road that can be applied in the preliminary feasibility stage. The proposed system is composed of three modules that estimate construction costs, land acquisition costs, and O&M costs. Based on the road route, the proposed system analyzes cross-sections through the topography and subsequently determines the probable road, bridge, and tunnel sections, and their project costs. Overall, the proposed system could assist a reasonable decision making for best route selection and further facilitate improved project delivery.

The Building Information Modeling (BIM) approach has revolutionized the way buildings are designed and constructed. The BIM design method - combined with web services, grid and cloud computing power - opens the door for construction engineers to improve the building design through enabling them to run advanced structural analyses for design alternatives quickly with low cost. However, the high hard- and software cost for complex computations like parametric studies are usually reserved for big companies or research facilities. This paper introduces an ongoing research with the project SE-Lab (http:/www.selba.eu) to develop a web-based Structural Engineering platform which allows small and medium enterprises (SMEs) to bundle their already available computing resources for complex simulations. Furthermore it provides data management functions, supports the creation of model variations and offers a collaboration layer to experts of different disciplines.

Managing changes is critical for a successful, energy-efficient, retrofit project. Good change management (CM) enables the evaluation of change dependencies and effects, and it is essential to controlling and mitigating failure factors in projects. For example, inappropriate management may generate disruptive impacts on energy efficiency goals. The use of Building Information Modeling (BIM)has facilitated the delivery of both new build and retrofit projects; but, there is inadequate support for the management of changes, and very little research has been conducted to integrate CM processes within BIM. This paper aims to specify an integrated framework for embedding CM in BIM. The framework has been developed within the BIM Data Hub project, which focuses on developing a central repository of building information to manage potential changes to IFC-based models. Current work on the BIM Data Hub focuses on retrieving domain-specific information from IFC models to conduct energy analysis. The outcomes of the analysis may result in recommendations for better energy performance, which would trigger potential changes. Such changes should be adequately managed across the building lifecycle. A comprehensive review of literature was conducted, including the developments and current status of CM and BIM adoption in energy-efficient retrofits. The requirements and challenges for the integration of CM and BIM Data Hub were also investigated. Subsequently, the paper formulated a mechanism for how changes resulting from workflow execution can be updated on BIM models, and how change information can be disseminated among team members. A system platform was developed based on the integrated framework. Finally, the contributions and recommendations for future research are presented.

Building information modeling (BIM) is one of the most recent technologies introduced to the design and construction industry. Currently, some educational institutions are requiring a BIM component for new construction. The aim of this research was to investigate the current extent of BIM use on educational facility projects. A survey inquiring about the current use of BIM, BIM benefits, perceived obstacles to using BIM, and the importance of particular BIM procedures was distributed to architecture, engineering and construction (AEC) professionals who have experience with educational facilities projects. The survey responses were analyzed using descriptive statistics. The survey results showed that the majority of the companies were using BIM. Many of the professionals who do not use BIM claimed to have no interest in using BIM. The largest proportion of the respondents perceived clients to be the driving force behind the use of BIM on educational facilities projects. Most respondents agreed that BIM was useful for increasing client engagement by providing clearer understanding of the projects through 3D visualization. While most of the respondents believed that design-build was the best method to deliver educational facilities projects using BIM, the majority of the respondents still used the design-bid-build method. This research helped gain insight into the general opinions of BIM users across the different disciplines involved in designing and constructing educational facilities. These research findings can be used to assist AEC companies that are interested in implementing BIM on the educational facilities projects.

This paper presents a practical application for the integration of Building Information Modeling (BIM) with scheduling and cost planning. It also describes the steps undertaken to plan and re-plan a project at each new decision taken by the multidisciplinary team. The study was conducted during the development of a low income housing enterprise near the city of Curitiba in Brazil. The undertaken application demonstrates how to extract information from the BIM model for use in production planning and control on site construction. Throughout the work breakdown structure and the unit costs for bill of materials, the model can be integrated with planning and helps the execution phase as well. With 4D/5D simulation, the information and decision-making of the design phase is taken to the construction site. The results show some decisions and uses of the integrated model in the design phase and in production planning and control on the construction site. Some difficulties experienced by the development team are also reported. The main conclusions of this study confirm the advantages and disadvantages of using 4D/5D BIM modeling found in the literature, such as supporting lean construction principles on production.

Building Information Modeling (BIM) is often perceived as a software tool that is applicable solely for designing and constructing buildings. BIM is more than just a software tool. It is a process that can enhance collaboration between project participants through three dimensional (3D) intelligent models, and it can be effectively used for designing, constructing, operating and managing any type of facility, including those for horizontal infrastructure. According to a recent smart market report by McGraw Hill, an increasing number of horizontal projects are now taking advantage of a process that is similar to BIM. In order to recognize the special needs of horizontal projects, the Civil Information Modeling (CiM) moniker has been adopted by the participants of these projects to describe the process that is equivalent to BIM. Some innovative contractors for horizontal projects are the early users of CiM and some state Departments of Transportation (DOTs) have also started adopting CiM. Furthermore, some DOTs also take advantage of advanced data collection technologies, such as LIDAR, that generate surveying data in 3D point cloud form which can be used as basis for 3D design that allows the entire workflow to be in 3D format. This paper presents content regarding the analysis results of interviews conducted with officials of the Iowa and Missouri DOTs who are involved with CiM implementation. It reviews the driving forces and challenges, as well as the benefits of using 3D intelligent models throughout the project development process and on into the operation and maintenance stages from DOT's perspectives. It explores current CiM practices while providing a gap analysis that defines what remains to be done in order to fully implement CiM.

This article proposes a metamodel to describe the use context of collaborative 4D modeling in Architecture, Engineering and Construction. While interaction with three-dimensional models has been extensively discussed in the literature, the interaction principles with the fourth dimension are much less treated. It is indeed a challenging issue according to the characteristics of the construction industry. The proposed metamodel is a preliminary step toward the proposal of adapted and/or innovative visualization and interaction mechanisms in collaborative 4D tools. It allows a good understanding of the collaborative 4D simulation activity and the identification of the main variables to consider from a high level point of view.

Construction industrialization is very much the trend in the construction industry of China. The deep integration of informatization and industrialization is the inevitable course of transformation and upgrading of the construction industry. Based on this, from the perspective of supply chain optimization management, we developed a software platform system and integrated all the project members of precast components (PC) into this platform. On this unified platform, the companies work collaboratively. Established on the basis of Building Information Modeling (BIM), this platform is a digital lean construction platform to integrate virtual construction technology, internet of things technology, cloud services technology, remote monitoring technology and high-end aided engineering equipment. On the platform, the whole construction project is under the control of the supply chain management and companies can achieve the targets, like: (1) optimization of business process; (2) shortest cycle; (3) lowest cost; (4) minimum inventory; (5) faster cash flow; and (6) enterprise value maximization. In the actual case, the achievements of the prefabricated digital lean build platform based on supply chain were shown and the developments of the platform for the future were discussed.

The preliminary stage of a residential real estate project is of great importance, but it is also known to be inefficient. However, a residential real estate project contains numerous built standard units such as dwelling units and floors. By introducing BIM, this research tapped the full potential advantage for improving the performance of the preliminary plan modeling in residential real estate projects. This research proposed a standard-unit-based modeling approach which contains 3 main steps: (1) standard unit management; (2) rapid plan modeling; and (3) in-time estimation. By integrating functions such as intelligent standard unit boundary revision, sun analysis, multi-level and information-based model visualization, a prototype system was developed based on this approach and was applied to a real estate project in Xian, China. The results indicate that this approach has the potential to improve the efficiency and quality of a preliminary plan.

Building Information Modeling (BIM) is the subject of one of the most significant current discussions in AEC industry. The amount of research on different aspects of BIM has increased to show how this groundbreaking approach has impacted the industry. One widely used method to research on BIM is developing and measuring metrics to assess BIM implementation. This research investigates metrics developed in peer-reviewed papers to find trends and gaps in BIM implementation assessment. This paper presents a method for developing a comprehensive framework of metrics to be used throughout the industry and academia to measure BIM implementation aspects and goals. By reviewing the ASCE database, this paper shows that most research has focused on BIM outcomes and, therefore, there is an extensive gap in research on BIM Input and BIM Process Assessment (e.g. evaluating human-technology interactions, collaboration, modeling performance, etc.).

As an initial stage study to effectively apply Building Information Modeling (BIM) to railway infrastructure, this study proposes measures of Industry Foundation Classes (IFC)-based information modeling of railroad bridges, which is a representative structure of railway infrastructure, and provides conceptual methods to utilize this measure. For this, firstly, IFC additional entity reflecting functional properties of the railroad bridge was suggested. Secondly, information modeling and management methods of railroad bridges using the current version of IFC were proposed. Thirdly, a connection method of external information and IFC-based railroad model was presented. Here, the study utilized necessary information for the calculation of carbon dioxide production. Lastly, the applicability of information model of railroad bridge based on BIM was examined by applying the above-mentioned methodology to two types of actual railroad bridges.

The engineering design process is a complicated activity. It is often characterized by multi-disciplinary teams in multiple places working together on a single project, using different models and software tools. In addition, such activities generate a large amount of data that require exchange among designers and stages of the work. In industry, the current collaboration approaches often focus on integrating and managing multiple models from multi-designers. Building Information Modelling (BIM) is playing a major role in facilitating collaboration. BIM provides an opportunity to electronically model and manage the vast amount of information embedded in a building project, from conception to completion. In the building design process, changes and modifications are inevitable even in the contemporary BIM approach. Such changes need to be well managed to keep track of changes to ensure that designers have an up-to-date version of the BIM model. The main goal of this research is to develop a collaborative BIM platform that tackles the challenges of integrating object versioning, as a change management approach, and an IFC model, as data representation of BIM. This has been done through suggesting new IFC extensions to add further concepts representing the history of changing to any object of the model. It also explores possibilities of adding or merging object-based change information to existing BIM models to enable the representation of design intentions, identification of affected changes numerically and visually. A prototype system is implemented in C#, using .NET framework and Revit API platform. This paper concludes that the proposed system can contribute to improving collaboration - in terms of tracking and management of affected changes during multi-disciplinary design process.

The government's construction strategy requires construction projects for central government to implement level 2 building information modelling as a minimum by 2016. Since it was published, a number of specifications, plans and processes have been released. Government has been involved in their production through being part of steering groups and explaining what they, as construction clients and occupiers of a huge number of built assets, need from the industry. Department projects have also been used to trial new methods and provide feedback from both the client's and the project team's point of view. The government's involvement has resulted in a coordinated response from an industry that is traditionally very fragmented and introduced a real impetus for changing the way the construction industry works and embracing digital technology.

The construction design industry involves multiple stakeholders who may carry out their job from widely distributed locations. Therefore, the interaction between those participants is often the cause of mistakes and misunderstandings due to a lack of interoperability. The UK Government will require all those engaged in the design, construction and management of publicly funded buildings and infrastructure to share that process by 2016 (Cabinet Office 2011). However, as stated by UK government reports, the lack of collaboration and interoperability causes not efficient benefit in the business context in the AEC industry. This research identified unstructured data, information consistency, data and information mapping and knowledge evaluation as the key challenges on the level of interoperability which professionals face constantly in the UK construction industry. This research has been structured using the interpretivist philosophy and qualitative approach to thoroughly explore the challenges of using unstructured data in construction engineering design in the UK. The data collection method of this research will employ semi-structured interviews with structured engineering in the UK and two different cases have been selected to conduct a cross-case analysis that will compare and contrast cases.

The main challenges in automating the regulatory compliance checking of building engineering designs are the availability of computable representations of the building and the regulatory knowledge, as well as a system that can process and manage these representations effectively. The emergence of Building Information Modelling (BIM) and Industry Foundation Classes (IFC) at the start of the millennium has sparked useful research in the area of sharing building information effectively; but, challenges remain with producing a practical and manageable regulatory knowledge representation that can be processed effectively by a compliance checking system. Research is being conducted to develop a two-part regulatory knowledge representation which can be maintained independently by designers and regulators. One part is a set of compliant design procedures modelled as Business Process Diagrams (BPD) using an open standard Business Process Model and Notation (BPMN). The other part is the associated regulatory constraints and rules encoded in a computable format suitable for execution with the BPMN. This paper reports on a set of guidelines developed for the purposes of encoding regulatory knowledge into the proposed computable representation. A verification method (C/VM2) prescribed by the New Zealand Building Code (NZBC) for the performance-based design of buildings related to fire safety has been selected as a case study to illustrate the encoding process. These guidelines are adaptable for encoding the entire NZBC.

It is difficult - and most of the time virtually impossible in reality - to conduct an evacuation test to study human behavior in the building condition during emergency situations (e.g. a burning building). Therefore, a serious game engine integrated with rich building information can provide an effective and efficient alternative. Anew serious gaming approach, based on Building Information Modeling (BIM), integrated with rich building information can simulate different emergency situations. It can also provide a 3D visualization and an interactive way for exploration of the effect of building conditions on human behavior during the evacuation process. However, human behavior and reaction to the emergency environment is one of the most important, but hard to predict, perspectives in the prediction of emergency evacuation time and results. Consequently, the development of a human library that contains validated human egress behaviors is the key to the simulation of evacuation in an emergency environment and the development of an accurate emergency evacuation analysis. This study develops the framework to build the human library through a BIM-based gaming environment. Parameters of human beings that should be considered are discussed and the values of these parameters are collected from the players of the developed emergency scenario (game). The repository of the human library is based on the framework of Agent Based Modeling (ABM) where human behavioral data is encapsulated as methods of agents. To overcome the limitations related to individual human factors, the hypothesis is that human behavior can be explored in a serious cyber game, and the decision made by the human in the game scenario is identical to the decision during the same situation in the real world.

Facility owners play a vital role in the Architecture, Engineering, Construction, and Operations (AECO) industry to improve the quality of building information modeling (BIM) execution. However, research shows that BIM adoption by owners is still in its early stages. Owners' requirements documentation, their assessment of the quality and accuracy of BIM deliverables, and their continued use of BIM during Facilities Management (FM) are critical to reaping the full life-cycle benefits of this technology. In order to improve facility owners' execution of BIM, it is critical that their BIM competency be assessed. Using the Delphi technique, this research identified and prioritized 66critical BIM competency factors that building owners must possess using the perceptions of 21 pre-qualified BIM experts representing several diverse roles in the AECO industry. Based on the results of this study, a BIM competency evaluation framework for owners is proposed.

Nowadays, facility management (FM) teams are facing challenges to generate accurate and semantically-rich as-is BIMs for existing buildings. Current model creation approaches, such as model generation based on point cloud data, mainly capture geometric information of a building and lack in providing additional semantic information about components and other project information. This paper provides the results of a detailed case study aimed at leveraging existing data sources (e.g., archived documents and data in FM systems) to generate accurate and semantically-rich as-is BIMs. The initial findings from the case study highlighted two main challenges associated with model generation from existing data sources: information extraction and integration. Existing information for different components is typically stored in heterogeneous data sources with various formats and quality and, hence, requires different approaches to extract information. The findings also showed that almost 40% of the component attributes investigated had conflicting values in existing sources. In order to address these challenges, formalized approaches are required to support conflict resolution, data extraction and integration.

Currently, work on enabling the use of building and construction-related concept libraries is being carried out in a number of disparate initiatives. The Norwegian reference implementation of the building SMART Data Dictionary (bSDD), the Dutch initiative for a concept library for the infrastructural sector (CB-NL), the Concept Model Ontology (CMO) and the generation of meta-data for long-term archival of BIM data in the context of the EU-project "Durable Architectural Knowledge" (DURAARK) share a great number of common aims and goals. These cover the areas of the general conceptual architecture, governance strategies for the content, accessibility and interfaces, as well as technical aspects of implementations and others. In this paper, the ongoing collaborative work on a harmonized framework for networked, distributed concept libraries is introduced and discussed. It is shown how such systems may be used to expose the concepts for semantic mash-up scenarios in the context of the Linked Open Data (LOD) initiative. A number of use-cases that demonstrate the potential applications of such systems in various interoperability scenarios are illustrated and discussed.

The increasing focus on Building Information Modeling (BIM) enables massive utilization of model checking software. Several software applications, such as Solibri and Navisworks, are applicable with a large list of powerful functions. Existing computer-supported model checking applications are mainly concentrated on verifying various codes and constructability based on as-designed 3D model which derived from 3D design results or 2D drawings. The effectiveness of these kinds of model check largely relies on the accuracy of the as-designed 3D model itself. Unfortunately, rare research is implemented to review the as-designed 3D model and assure information accuracy. This paper develops a systematic approach for BIM model fitness review through predefined standards. Firstly, the paper starts by discussing the need for automated BIM model review and analysing the limitations of existing model checking efforts in this regard. Then, an overview of the proposed BIM Model Fitness Review System (BIM²FRS) is provided. Thirdly, the paper presents a case study to validate the BIM²FRS. The result shows that: (1) the system can efficiently assess BIM model fitness and support BIM model management; (2) the development of the ABIM²R system is still very young; and (3) only limited types of model fitness review are presented.

With an ever-increasing cooling energy demand of buildings in hot and humid climates like in Florida, using a well-designed window-shading system is considered as an efficient strategy that minimizes the direct sunlight reaching indoors and thus, reduces the overall energy loads. While reduction in energy loads is important, the indoor comfort of occupants should not be compromised. Individual thermal and solar properties of glazing and shading systems only provide information based on static evaluations. It is, therefore, very important to assess the efficiency of these systems as a whole assembly under the site-specific conditions. Using different types of window-shading assemblies, this research was conducted to evaluate the impact on the overall performance of a south-facing building in Floridathrough:(1) calculating total energy consumption; and (2) analyzing indoor thermal and visual comfort. The results were then presented to suggest economic and efficient design strategies for south-oriented facades.

Land use/Land cover (LULC) change is one of the key reasons for the Urban Heat Island (UHI) dynamic. Previous studies focused on the relationship of urban sprawl and emergence of UHI; but, less attention was paid to how urban regeneration progress influences the thermal environment in built-up regions. In this paper, a comparative study of Kowloon, Kuwn Tong and Kwai Tsing was conducted on the LULC and Urban Heat Island Intensity (UHII) in 2000 and 2010. The study investigated the effect of urban regeneration progress on thermal behavior of the built-up environment. Landsat 7 ETM+ data was used to retrieve the UHII of the two periods in the study area. A spatial quantitative analysis was made through the integration of Remote Sensing (RS) and the Geographical Information System (GIS) analysis tool. The results presented an evident enhancement of UHI in Kowloon East within the 10 years of urban development. The study results provides reference to optimize the master plan of Kowloon East and contribute to the innovative thinking in applying scientific methods to support the decision-making in urban regeneration schemes to avoid environmental issues that the urban regeneration process may bring about.

This empirical research focuses on the possible interoperability between Building Information Modeling (BIM), the building energy performance requirements and Building Performance Simulation (BPS) software. Within the practical use of these technologies, sample paths will be analyzed within the interoperability processes between BIM and BPS. The aim is to support architects and energy consultants in choosing the most appropriate software workflow to analyze buildings and fulfill the performance requirements given by the countries' laws. Several study cases in interoperability and a summary of current research are presented and discussed. Finally, a novel map of interoperability between these three areas is presented.

This research focuses on a new workflow between Space Layout Planning (SLP) and Building Performance Simulation (BPS) fields for the early stages of building design aimed at reducing energy needs of a building and improving indoor environment quality. Parameters of environmental performance requirements (such as temperature, view, and acoustics) from different international norms were selected. The purpose is to link these performance parameters to a graph file. This graph supports schematic design tasks during the creation of architectural floor plans. Programming tests were run to add the information to the graph. A prototype for the early stages of the design is presented. In this prototype, designers can visualize performance information during schematic design of floor-plans of a building. A study case is presented to demonstrate the usability of the concept.

Designers and facility managers increasingly rely on Building Energy Performance Simulation (BEPS) tools to analyze complex building systems and determine whole building energy performance. A major barrier in the deployment of BEPS tools has been the lack of process interoperability and the magnitude and complexity of the required input data that often results in inaccurate and incomplete simulation models and simulation results. This paper introduces a Simulation Resource Framework that aims to gives end-users access to varied simulation resource libraries and energy-related design decision templates capturing weather data, occupancy activities, construction types and material thermal properties when configuring simulation models. Such templates and resources, bringing in expert know-how from theoretical studies and past experience, are especially valuable in early design where knowledge about the building's performance and components is incomplete but fundamental decisions have to be made. In the paper, we describe the overall concept and development approach of the suggested framework and its integration in a broader Multi-Model environment enabling interoperability of BIM and any needed non-BIM resources hosted in the Simulation Resource Framework (SRF).

The recent advance of Building Information Modelling (BIM) and the related needs for BIM-based interoperability of more and more specialized AEC tools in various construction subdomains showed that: (1) a global model for all data in a construction project is neither a realistic nor practical target, and; (2) BIM data typically have to be combined with other kinds of construction-related data to be efficiently applied in real tasks. This paper addresses the issue of BIM extension for such multi-model domain tasks on the basis of work done in the frames of the EU project HESMOS for the development of an energy-enhanced BIM framework (eeBIM) enabling the integration of multiple needed resources (i.e., climate, occupancy, and material data) and the interoperability of various energy analysis and monitoring tools in an Integrated Virtual Energy Lab Platform (IVEL). It explores the pros and cons of three principal approaches -(1) extending the BIM Schema; (2) extending the BIM data; and (3) using a Link Model - before focusing, in particula,r on the latter approach which provides for greatest generality, modularity and application scope as it does not require changes in the BIM schema and guarantees maintenance of each model within its own domain. The generation of the eeBIM model from initial architectural CAD-BIM data and future research plans completes the presentation.

The maintenance of Heating Ventilation and Air Conditioning (HVAC) systems is one of the fundamental activities in facilities management groups. HVAC systems are configured from basic types of components, such as dampers, fans, valves and coils. There are usually multiple instances of the same type of components performing different functions in an HVAC system. For example, in relation to dampers, an HVAC system can contain an outside air damper, a discharge air damper, a return air damper, a mixed air damper, and multiple variable air volume dampers. It is also a similar case for other components such as valves, coils and fans. When HVAC mechanics perform maintenance activities, they usually need to check HVAC components with specific functions and know information about components, such as "where is the outside air damper?" The information related with different HVAC components can be represented and exchanged using Building Information Models (BIM). Among BIM data standards, IFC represents more information in relation to HVAC for Facilities Management (FM) purpose. However, the bottleneck of using IFC to provide information support for HVAC maintenance is that current IFC standard does not differentiate functions of HVAC components of the same type. Thus, it is not possible to identify HVAC components with specific functions and retrieve their information from an IFC file directly. This study presents the need for an approach to deduce the functionalities of HVAC components from their existing topological information represented in IFC files. This approach, once formalized, can be used as a basis to automatically retrieve required information from IFC-based BIM for HVAC mechanics during maintenance tasks.

The INNOVance research project, funded by the Italian Ministry of Economic Development, wants to push a radical innovation into the Italian Construction sector by creating the Italian construction database - containing information about products, works, and spaces - along the whole construction service life. This research wants to improve the efficiency in using and maintaining objects' information - which is achieved by linking continually updated, extensible life-cycle objects data to independent software using Building Information Models - throughout the entire life cycle. The work done consists of three main steps: (1) to give an unambiguous name to everything in the construction process, from products to spaces, from activities to buildings, etc.;(2) to define structure and content of the information related to each named entity; and (3) to pair each entity in the database with a BIM object. The multitude of rules, definitions and practices that characterizes the Italian construction sector causes difficulties in data transmission among stakeholders; so, the first priority of INNOVance was to create a coding system based on a standardized and unequivocal name. To manage and use information through the construction process, technical datasheets have been defined and standardized among homogeneous object categories (construction products, spaces, construction operations, etc.) to allow users to easily and quickly compare and retrieve information. Data will be freely accessible throughout a web-based portal that relies on the INNOVance database. In addition, specific plug-ins allow creating, updating and linking objects directly from BIM software. At the end of the project, database interoperability is guaranteed by Building Smart Italy with the adoption of the IFC protocol.

Building Information Modeling (BIM) has been found to be one of the most promising advancements in the Architecture, Engineering, Construction, and Operations and Management (AECOM) industry. BIM integrates the geometric and parametric properties of the 3D model of a facility with all the information and properties of building features and components. However, finding the current location of a specific component or navigation through an unfamiliar facility can be difficult and time-consuming. Visualizing the location in real time can provide the ability to reduce the time for manual searching and locating. This paper demonstrates how the BIM model can be utilized for real-time visualization and localization when integrated with sensing technologies. Real-time visualization and localization require context-aware information (e.g. space, location, and time) in order to function properly. Therefore, the BIM model can provide the spatial relationships while the location sensing technology can provide location and time information. Current indoor localization techniques utilize probabilistic algorithms to estimate landmarks or components, which often require great computational power. Since the model contains the exact locations of components, utilizing BIM provides the advantage of not needing to estimate the true location of the landmarks, thereby drastically reducing the complexity and computing time of the algorithm.

Facilities maintenance tasks require gathering and sharing large amounts of information related to facilities components. This information covers historical inspection data and operation information. Despite the availability of sophisticated Computerized Maintenance Management Systems (CMMSs), these systems focus on the data management aspects (i.e. work orders, resource management and asset inventory) and lack the functions required to facilitate data collection and data entry, as well as data retrieval and visualization when and where needed. Building Information Modeling (BIM) provides opportunities to improve the efficiency of CMMSs by sharing building information between different applications/users throughout the lifecycle of the facility. This paper proposes a framework for a collaborative BIM-based Markerless Mixed Reality (BIM3R). The framework integrates CMMS, BIM, and video-based tracking in a BIM3R setting to retrieve information based on time (e.g. inspection schedule) and the location of the user, visualize maintenance operations, and support collaboration between the field and the office to enhance decision making. Finally, a prototype system is implemented and a case study is applied to demonstrate the feasibility of the proposed approach.

An often-introduced claim is that BIM can be a powerful tool for facility managers to improve buildings' performance and manage operations more efficiently throughout the life-cycle of buildings. Although this claim has been common since the early introduction of BIM, there is relatively little information about the real use on BIM in the operation and maintenance of buildings. Even most large public owners who have been early adopters of BIM (such as GSA, USACE or Senate Properties) have used BIM more in managing their construction projects than implementing it into their FM activities. The benefits of BIM for design and construction are relatively well studied and documented, but there is little evidence of the benefits of BIM in the operational phase. In addition, the challenges involved in shifting from traditional FM processes to new BIM-based processes are not well-known. In this paper, we document some of the issues involved in the adoption of BIM in FM and identify some of the enablers and barriers to BIM implementation in FM. The findings are based on a case study carried out during the final design and construction phase of Manchester Town Hall Complex, a major re-development project in the UK. Results confirm the lack of awareness of the potential of BIM in the operation phase and the need for clear guidelines for the implementation of BIM in FM defining required level of integration, standard BIM protocols and the key deliverables for FM purposes.

Building Information Modeling has been a catalyst for process change in the AEC industry in terms of earlier decision-making and in identifying the need for more precise and accurate information throughout the design and construction process. Due to the use of collaborative project delivery methods and the owner's participation on the project team, the same catalyst is now forcing owners to provide more precise information regarding required deliverables. Consideration of the desired intent for the utilization of information during the life-cycle of the building is necessary to determine the optimal information requirements. From the time of project conception, and throughout all project phases, opportunities exist to collect important information. The industry has responded with the development of consulting services to meet the owner's needs and also to assist with recommended processes for owners to operationalize the project closeout information. Owner guides and standards are purposely kept generic to suit the needs of all owners and rarely attempt to address the specific data needs at the point of close-out. It is common for some owners to adopt another organization's existing contract deliverable statements, but owners should articulate their own meaningful verbiage to achieve the desired closeout requirements. There is an excessive number of decisions required from the owner in determining their specific organizational needs, which present various challenges to the owner, but involve instrumental steps to begin constructing meaningful BIM attribute data. An understanding of the taxonomy and standards for the information will assist owners with operationalizing the handover deliverables. Additionally, defining the taxonomy for owner information will further delineate the LOD500 for future research.

Simulation models are typically developed for construction operations to maximize output of resources and minimize operational cost. Traditional simulation methods deal with development of activity cycle diagrams based on key activities in construction operations. These methods do not consider spatial constraints at the site directly. As a result, spatial conflicts occur and desired output level is not achieved. Congestion analysis in construction site layout planning depends upon such spatial constraints and movement of resources inside the site. This research implements a cell-based simulation model with spatial consideration for construction site layout planning. The objective of this research is to incorporate congestion analysis into simulation process to improve construction site layout plan. A case study is done involving cyclic earthmoving operation. Location data from moving equipment is collected using Global Positioning System for accurate spatial reference. Real data from site is fed into the simulation model for realistic representation of the operation. A cell-based continuous simulation model is developed for visualizing congestion. A new method for quantifying congestion is proposed. This method will help decision-makers in developing a site layout plan based on movement of resources. The potential for congestion can be determined before implementing a layout onto the site. It will aid in comparing alternative site layout plans and provide insight on consequences of varying the number of resources on site congestion. It will also serve as a training and educational tool for construction managers.

This paper proposes a generalized architecture that suggests an approach to extend utilization of Virtual Environments (VEs) in Civil Engineering. The architecture allows the combination of: (a) approaches to visualize previously conducted construction activities that involved multiple construction machines and (b) methods that support demonstrating and evaluating alternative operational strategies. The proposed architecture was tested by developing and applying a specialized VE oriented to review asphalt compaction operational strategies and explore alternatives. To allow the assessment of the continuity and consistency of both real and demonstrated activities, we outlined a set of special indicators to characterize compaction processes. The VEs developed according to the proposed architecture ultimately aim to support communication and reflection amidst construction professionals who possess different sets of knowledge and experience. The VE-induced interactions are expected to stimulate knowledge integration, collaborative sense-making, learning, and process improvement.

In construction photogrammetric surveying, it is imperative to convert the relative scale of a 3D model into absolute measurements so that geometric measurements can be taken. Previous work suggests this can be done through the determination of a reference line in absolute units, but the position and quantity of reference lines has not been investigated. This paper attempts to characterize the behavior of different strategies in selecting reference lines. Factors including relative position of the reference line, the number of reference lines, and spatial relationships of the reference lines are considered. Three infrastructure objects serve as the test beds, and experiments using various layouts of scale bars (calibrated reference lines) are conducted on each object. The surveying results are then compared with ground truth data, which allows for accuracy determination and aids in determining the best strategy in selecting reference lines for scale fixing. The results from these experiments show that one horizontal reference line in the middle of the object performed with consistent accuracy; but, if a specific area on the object needs more accurate measurements, it is best to select a reference line in that area. Using three reference lines is ideal from a time and accuracy improvement perspective.

The construction procedure in mechanized tunneling is affected by a complex interaction of logistic processes. Due to restrictive factors (like limited space on construction sites), a just-in-time delivery of material is required for production purposes. Slight differences of the production rate of a Tunnel Boring Machine (TBM) have huge impacts at the logistical chain. Therefore, logistic management is one of the key factors responsible for the success and profitability of tunneling projects. In this paper, a discrete event simulation model is presented that supports tunneling experts in the planning process and can be applied in the construction phase as a tool for decision analysis. Since each TBM is unique, it has a unique demand for logistic solutions. Therefore, the simulation model is implemented in a modular manner such that it can be applied to a vast number of different projects in mechanized tunneling. The properties of the construction site and the TBM are freely configurable. To show the functionality of the model, a fictive demonstration model was conducted. It illustrates the influence of different logistic processes on the production rate of a TBM as well as the complex interactions of single logistic processes in the supply chain of a construction site.

Energy conservation measures are needed to prevent the world from moving in an unsustainable direction. Actions targeting the building sector are especially vital since it stands for a large share of the total energy use. The objective of this research is, therefore, to provide a framework for using visualization of aggregated energy use over time in a district heating network to stakeholders. This is fulfilled by integrating building information and energy data from a district heating supplier. The integration of building information and energy data makes it possible to identify high energy consumers through a performance visualization interface. Furthermore, the interface is connected to a collaboration hub which offers a communication opportunity between consumers, suppliers, energy advisors and urban planners. Additionally, a stakeholder management approach is proposed to support the energy advisor in managing and selecting the consumers to target with advice and actions. The visualization, collaboration and the stakeholder component of the proposed system creates a Planning Support System (PSS) by which the citizens, energy advisors and urban planners can monitor the use of energy and also suggest actions to decrease the energy use of buildings. The next step of this research will be to evaluate and test the PSS together with energy advisors of 20 municipalities in Sweden.

This paper presents an approach for inspection of construction enabled via building information modeling (BIM). It meets the following criteria: (1) all major inspection tasks and locations are determined before the site inspection trip; (2) inspectors can easily retrieve the prepared images generated from the BIM model and related construction information required to complete the inspection tasks without complicated manipulation of the BIM model during inspection; and (3) the inspector's tasks are straight-forward and mainly involve data collection. This means that the inspector's tasks at the construction site are well defined and free of possible interference from site engineers. In the ongoing research presented in this paper, a BIM-enabled construction inspection system is prototyped based on the proposed approach. The system framework and user interface (UI) are discussed and designed to achieve effective and efficient inspection of construction.

Object detection and tracking is a challenging problem in the dynamic construction environment, especially for objects with kinematic joints and changing poses, e.g. excavators. This paper presents a kinematic key nodes model for dynamically detecting and locating movable objects in construction sites using color-depth cameras. The key nodes model is designed by first analyzing kinematic constraints from mechanic specifications of interested construction site objects and then building representative segmented contour templates under supervision. Feature matching is realized by comparing the real object components and segmented contour templates in a traversal order of the tree structure for all the key nodes. Since color-depth cameras capture not only images, but also the distance between detected objects and the camera itself in a format of three-dimensional (3D) point clouds, the 3D spatial location of an object is obtained by linking the image coordinate of each detected key node with the 3D point coordinates. This proposed framework showed great potential in construction monitoring and safety management.

The authors have been developing methods capable of deducing the Synchronized Multi-Site Scheduling using the interface matrix obtained from the relationship between preceding and following of the tasks for the construction work with a repetitive nature. In this study, several structural construction plans were estimated by carrying out simulations using the construction delivery time (which are the criteria for the structural construction method plans) as objective variables. In this study, the Synchronized Multi-Site Scheduling method is in conjunction with the quantity information of the 3D model. Redefine the 3D model for using the technique of dividing and combining the 3D model utilized in the construction simulations. Various simulations created by the 3D model are redefined with reference to the productivity data and unit price information. In concrete terms, the performance of each structural construction method plan was estimated by carrying out a four-process simulation for the skeleton construction work above the ground for a high-rise RC office building using a site division and a component division as variables.

Construction scheduling is usually limited to the documentation of one final construction schedule, and construction alternatives that might have been considered during the planning process are usually not included in the final schedule. Moreover, a formal control of construction schedules in terms of completeness and correctness is very limited because existing methods, such as 4D visualization, are insufficiently integrated into the construction planning process. This paper addresses the development of a software framework that has been designed to support the process of construction scheduling. As will be shown in this paper, the process of construction scheduling, which is usually carried out manually, is conducted automatically to a large extent using building information models (BIM) and 4D visualization. Due to the logical interconnections of BIM objects and construction tasks, flexible schedules and visual representations of construction processes are automatically generated without permanent human interaction.

This paper examines the adoption of object-based modeling software across design and construction team members during project delivery. Drawing on insights from sociology, management theory and innovation studies, the paper investigates changes surrounding technology adoption and subsequent management-based innovation. Using empirical data from a case study, analysis focuses on adoption of software, the evolution of new digital and social networks, and subsequent innovations in management. The paper has three main contributions. First, it identifies related literature and examines change processes surrounding software adoption and the management innovations that are triggered. Second, it explores rigidities in existing routines that challenge adoption and deployment, highlighting innovations that reconcile change conflicts. Third, it shows how the concept of management innovation in construction is valuable to an understanding IT adoption processes.

This paper represents the numerical analysis of the tunnel lining which was used for maintaining the old tunnel. An old tunnel covered with concrete is prone to deteriorate due to an aging effect and water penetration. In the rehabilitation of lining concrete, a steel plate and FRP (Fiber Reinforced Plastics) or carbon sheet have been applied. However, these sheets show small flexural rigidity and do not allow the penetrating water to flow out. In this paper, FRP corrugate sheet was proposed. The tunnel lining was made from FRP corrugate sheet that supported the concrete lining in the tunnel, allowing the water to flow and sweeping the moisture to the tunnel surface. The FRP corrugate sheet was supported by the anchor bolts. In numerical analyses, the finite element degenerate shell was adopted to represent the FRP sheet behavior. From the numerical analysis, the effectiveness of the FRP corrugate sheet was confirmed.

This paper examines the evaluation of BIM-enabled projects. It provides a critical review of the three main areas of measurement, namely:technology, organization/people and process. Using two documented case studies of BIM implementation, the paper illustrates the benefits realized by project owners and contractors, and illustrates a lack of attention relative to contextual factors affecting the adoption and deployment of BIM. The paper has three main contributions. First, it identifies and discusses the lack of and difficulty surrounding standardized assessment methods for evaluating BIM-enabled projects. Second, it proposes a conceptual model that includes contextual attributes and demonstrates how the proposed framework reaches beyond simple evaluation to encompass the documentation of BIM's benefits, lessons learned, challenges and adopted solutions. Third, it shows how the framework can account for existing business processes, organizational process assets, and enterprise level factors. The paper aims to provide a conceptual basis for evaluation and a starting point for benchmarking.

The site installation for a construction site should be optimized for the environment, the construction itself and the construction methods. To support the process of site installation planning, a perspective projection in combination with head tracking of the participants in the planning process is helpful. By this, clashes between the construction and site installation equipment can be avoided. However, when planning a site installation, the different perspectives of involved parties at the same time are needed. However, in a perspective projection, one cannot point out things so that others can see what is pointed at because all get the same perspective projection. Therefore, a multi-user environment with perspective projection is helpful. Furthermore, the interaction between different experts is needed to find the optimum. A perspective projection in combination with head tracking for multi-users can solve this problem. For quite some time, product models -like building information models - could be visualized in virtual reality. However, placing only the objects of site installation within this BIM model is not enough because a typical construction site changes dynamically during the construction time. Therefore, a product model linked with a time schedule to 4D construction model is needed as a base for the planning of the construction site. Based on that, the site installation can be developed according to the requirements of the construction process. Furthermore, the objects of site installation have to be modeled with their parameters. Thus, movements and process flows can be checked.

Building Information Model (BIM) technology combines a "virtual building" with extended information, removing the necessity to rely on imagination or experience to foresee the completed building. Viewing a construction project in 3-D includes spatial information that is difficult to convey in 2-D drawings and can reduce errors during construction. In addition to geometry, extended information - such as the properties of building components and the relationship between them - can also be included in models. However, 2-D drawings are still commonly used on sites. One main reason is that the manipulation of BIM models using a mouse is not intuitive and is often not appropriate in the site environment. This research focuses on developing an interactive interface for site workers to retrieve information from BIM models, allowing them to break through the limitations of 2-D drawings. The main feature in this research is a BIM viewer with Natural User Interface (NUI). The interface provides hand-based gesture control that allows BIM models to be navigated with ease. The main contribution of this research is to define gestures that are natural to users and to make the manipulation of BIM intuitive by fine-tuning the sensitivity between real movement and virtual movement. The next step of the research is to conduct a user test to validate the usability of our design.

In this study, we observed distributed construction engineering management teams as they discovered issues in building models while collaborating in a 3D virtual world. This paper contributes to visualization and building information modeling (BIM) literature by exploring how the affordances of the media-rich 3D environment of a virtual world support mutual discovery of construction coordination issues among team members. In Winter/Spring 2013, graduate and undergraduate students from four globally distributed universities met in three teams once a week for eleven weeks. Numerous communication affordances were available to the teams - both within and external to the virtual world - including voice, text chat, screen-sharing, and exploring avatar-scaled models imported into the virtual world. When exploring the imported model, individuals controlled their own viewpoint by "walking" through the building as an avatar using the arrow keys on a keyboard and, as a result, all members of the team were able to view the model together, regardless of BIM experience. We found the rate of issue discovery to be significantly higher in the avatar-scaled models compared to other methods of viewing the model - such as passively viewing the model on a 2D shared screen - indicating that bringing team members and building models into the same interactional space is more effective for quickly discovering coordination issues.

Virtual Reality (VR) technologies have been used in building design and construction for many years. VR has primarily been applied for design review, worker and end-user training, 3D coordination, marketing, and demonstration. Previous research shows that VR technologies, such as interactive virtual walkthroughs, help the design team effectively convey design ideas, aid in the evaluation of architectural alternatives, and assist in the identification of design errors. Despite the benefits, VR has not yet been widely adopted in actual design practice. This paper examines the use of a VR media and display system in the design process of an energy retrofit project and identifies the benefits and challenges of using VR technologies for the project. The project team had access to an immersive display system throughout the design process. A research team supported the design team with the development of virtual reality solutions. The research team also documented and evaluated the uses of the immersive display system through surveys and case study analysis techniques. The case study shows that using VR tools and an immersive display system makes the design meetings more productive and the reviews more effective, provided the VR models are developed with appropriate level of detail and functionalities. The industry still lacks a general understanding of the benefit and use cases of VR technology. In addition, the lack of expertise in VR tools and VR display systems also impedes the wider adoption of the VR technologies in the current practice.

Building Information Modeling (BIM) has gained wider acceptance in the Architecture/Engineering/Construction (A/E/C) industries in the U.S. and internationally. Capability of BIM technologies in early detection of spatial conflicts among various building systems and components concurrently designed by different design team members prior to construction has great potential in reducing construction delays, loss of productivity, and overall construction costs. Recent advancements in 3D point cloud technologies, such as 3D laser scanning, can greatly augment BIM technology applications in the A/E/C industry by providing a rapid three-dimensional capture of the built environment in great detail and accuracy. This paper discusses the current approaches of implementing 3D point cloud data in BIM and virtual design and construction (VDC) applications during various stages of a project lifecycle and the challenges associated with processing the huge amount of 3D point cloud data. Conversion from discrete 3D point cloud raster data to geometric/vector BIM data remains to be a labor-intensive process. The needs for intelligent geometric feature detection/reconstruction algorithms for automated point cloud processing and issues related to data management will be discussed. This paper also presents some innovative approaches for integrating 3D point cloud data with BIM to efficiently augment built environment design, construction, and management.

Steel structures construction continues to be one of the most hazardous jobs in the construction industry. Even with the strict application of international safety codes, the fatalities in the steel construction activity are more than any other site works. This fact demonstrates the need to improve the health and safety at steel construction sites. The objective of this paper, which is part of a Ph.D. thesis, is to identify how to apply novel technologies to enhance the workers' safety awareness on site. The paper proposes a methodology based on BIM model incorporating the 2D image data available from an actual project and the approved project plan. Enhancing all real images and comparing them withtheBIM model to expect the following site activities and their associated hazards, the hazards then will be presented to the site worker in an advanced visualization tool in order to control and minimize the risk.

There is a renewed interest in immersive visualization to navigate digital data-sets associated with large building and infrastructure projects. Following work with a fully immersive visualization facility at the University, this paper details the development of a complementary mobile visualization environment. It articulates progress on the requirements for this facility, the overall design of hardware and software, and the laboratory testing and planning for user pilots in construction applications. Like our fixed facility, this new light-weight mobile solution enables a group of users to navigate a 3D model at a 1:1 scale and to work collaboratively with structured asset information. However, it offers greater flexibility as two users can assemble and start using it at a new location within an hour. The solution has been developed and tested in a laboratory and will be piloted in engineering design review and stakeholder engagement applications on a major construction project.

Most studies of ICT introductions have their focus on one organization where the new ICT should support well-known activities in the organization. When ICT-introductions are aimed at starting, improving or changing inter-organizational collaboration, the situation is different. New tasks need to be formed and organizations meet on unknown grounds - not many studies have been done of this type of situation. Theories that are found to be useful in situations when ICT is introduced in one organization are not sufficient to account for all effects in an inter-organizational collaboration case. This paper explores how organizational theory can contribute to better understand the introduction of Virtual Reality for inter-organizational collaboration. Applying sense making and organizational boundaries to the three studies of Architecture-Engineering-Construction projects shows benefits for identifying and analyzing upcoming difficulties in a structured way.

In this paper, we present a new method for supporting onsite construction and facility management tasks by allowing field personnel to automatically have access to the latest project information in the form of Augmented Reality (AR) overlays - visually document onsite issues/progress, and communicate information with other personnel on or off site. Our near real-time and marker-less mobile augmented reality solution builds on top of a new image-based localization method for 3D point clouds that have been reconstructed using a Structure-from-Motion (SfM) pipeline and are clustered based on already available geo-location data. By using images captured from commodity smartphones/tablets, our method computes a precise 6-DOF pose for the camera and delivers relevant project information in the form of AR overlays. Our main contributions lie in efficient clustering of 3D point clouds and rapid computation of camera pose by detecting an appropriate cluster of 3D points. Compared to our previous work for AEC/FM mobile augmented reality applications, the experimental results demonstrate that the proposed clustering approach accelerates image-based localization using 3D point clouds, taking 1-2 seconds for a single localization.

The Architecture, Engineering, Construction, and Operations (AECO) industry and, specifically, the facility management domain are searching for new methods for increasing maintenance efficiency and productivity where critical decisions are constantly made to maintain the facility. New digital technologies are capable of enhancing this decision-making process by providing better means of accessing required information. In this research, BIM - together with mobile Augmented Reality (AR) - has been used for developing a system to access building information in facilities. AR has been considered as a viable option to replace the current approach of locating facility components using paper-based corrective/preventive maintenance work orders. The AR method was also assumed to reduce inefficiencies of data overload by providing facility managers with a BIM-based tool for visualizing their "real-world" environment with added interactive data. The hypothesis of this research is that bringing 3D BIM models of building components into an AR environment and making them accessible through handheld mobile devices would help the facility managers to locate those components easier and faster compared to facility managers' current approach of paper-based preventive/corrective maintenance work orders. A within-subjects user participation experiment and analysis was conducted to evaluate this hypothesis. The outcome of statistical analysis revealed that mobile AR-based environment would significantly enhance locating the right object in the facility in terms of the required time and number of errors. Although there were drift and registration problems while conducting the experiment, participants significantly preferred the AR condition to the paper one.

Traffic sign and mile-marker detection and classification are among the important components of highway asset management systems. The significant number of these high-quantity and low-cost assets in US highways can negatively impact the quality of any manual data collection and analysis. To address these challenges, this paper presents an efficient pipeline for video-based detection and classification of traffic signs and mile-markers based on color and shape criteria. Candidate extraction is based on finding the optimum RGB thresholds which yield high detection rates (very low false-negatives) while keeping the number of false-positives in check. The connected components from a thresholded image are extracted next. We use sliding windows, Haar-like features, and the AdaBoost learning method to classify the detected assets. Experimental results with an average classification accuracy of 79.30% on actual data collected from US-460 highway show the promise of the proposed method for reducing the time and effort required for developing traffic road asset inventories.

A city planning project with four participating architectural consortia was followed in 2007 and 2010. The City Planning Office required VR as a compulsory tool. Interviews with representatives of different professions revealed that VR was used to a minimum. Obviously, it was not enough to demand the use of VR to achieve the advantages it was expected to bring.

Photog-CAD® is software to aid prompt operations from conducting surveys to making designs and estimated expense for recovery in the collapsed area of slopes and river revetments caused by natural disaster. This software is intended to make a design and an estimate based on the 3D models created by processing pictures of the collapsed site from three directions using a close-photogrammetric technique. However, when taking pictures from the ground, there are many restrictions which often make the use of this software difficult. This research paper proves that it is efficient to use an unmanned aerial vehicle (UAV) which can take photographs from the sky above and reports a case study in which we efficiently conducted a survey using Photog-CAD® with the UAV, and made a design, estimate, and documents for the budget request.

The guidance in building evacuation during and after a disaster is an important and challenging problem, as the evacuees usually do not know the best route for evacuation and the static exit signals do not necessarily guide the evacuees to the right direction in dynamic situations. To find a best path in real-time within buildings is nontrivial. This paper proposes a distributed decision support system that efficiently computes the routes in real-time for building evacuation scenarios. Dijkstra's algorithm and Dynamic Programming are used for the route analysis. In the proposed approach, the physical system is composed of sensor nodes and decision nodes. The decision nodes, which are located at suitable locations for dynamic guidance, are equipped with information displays. The approach is evaluated in digital models and the authors built a 3D model with wall properties to be simulated with the Fire Dynamic Simulator (FDS). Fire spread and temperature distribution in the building under a mesh model are used as sensor input to test the proposed algorithm.

This study explores the system architecture of "ByggNett" ("BuildNetwork"), an initiative from the Norwegian government for the development of a new collaboration platform for exchange of information among all private and public actors in the entire construction industry. The study explores the ongoing Concept Evaluation project. The Norwegian initiative has a very inclusive approach and combines services and solutions from both public and commercial actors. Public projects do not focus on external information, and proliferation of this initiative can enable collaboration and exchange of experiences.

Delays in delivering spatial information to support the decisions about maintenance of bridges introduce stoppages into the bridge management workflow. Previous studies show that spatial data collection and analysis are major components of these inspection programs. However, the time-consuming spatial data processing causes days or weeks of delays in delivering the needed spatial information. Federal agencies, in many cases, either wait for the tedious spatial data processing or use partial data processing results containing high uncertainties. Using the processing of 3D laser scanning point clouds as an example, this paper examines the technical feasibility and scientific challenges of quantifying the data processing time and the quality (e.g., accuracy) of derived information (e.g., minimum under-clearance of a bridge) useful for bridge management. Different decisions need different geometric attributes and relationships with various accuracy requirements. The optimal data processing strategy varies with the needed information quality and time limits. It is difficult to manually analyze the time-quality trade-offs of spatial data processing due to its ad-hoc nature and large number of possible parameter settings in data processing workflows. The authors proposed a computational framework that automatically records data processing histories of engineers along with the engineering needs. Analyzing those histories lead to insights into the trade-offs between required computational complexity/time and quality of delivered spatial information. This paper presents time-quality analysis results from two bridge inspection cases.

Field documentation is an important link in the construction industry on the individual project basis and for the entire company operations. The information contained in the field documentation is the primary source for the management to monitor the status of the project and perform various analyses. This information also provides the basis to establish the historical cost data used for securing future work. The advancements in the information technology industry, especially in the mobile computing technologies, have provided many opportunities to computerize and automate the field information flow. Over the years, studies have examined various hardware technologies on their usability for fulfilling this task. This paper examines the past research from a usability point of view and focuses on the Graphic User Interface (GUI) part of the system. The study evaluated the usability properties of pictograms and pre-determined text lists as mechanisms for automated data entry on mobile computing devices. Results showed foremen and construction professionals performed visual search tasks faster with pictograms than with pre-determined text lists.

Double skin façade (DSF) systems are increasingly used in high-rise buildings in hot summer and cold winter climate cities for the enhancement of acoustic insulation, aesthetic appearance, thermal insulation, natural ventilation, and energy efficiency. However, inappropriate DSF configuration can cause an increase in the risk of overheating in the cavity space during summer, which is one of the main disadvantages of DSF systems. In order to improve DSF configuration, as a means of increasing energy efficiency, an effective analysis method for thermal performance evaluation that considers all possible thermal parameters should be used. However, widely used current analysis methods are mostly focused on the evaluation of thermal performance by changing the façade optical properties in the DSF cavity space. In addition, the opening system in DSF is mostly operated as one unit. Taking into consideration these limits, this study focuses on the fact that wind speed and ambient temperature can change the airflow movement in the cavity with opening operation. In addition, the temperature and heat flow in the cavity can differently affect inside thermal performance depending on the height of the room. It is important to consider all possible parameters that can affect thermal performance, including wind speed and building height, for effective thermal analysis in a DSF configuration. This study explored the applicability of a climate-responsive automatic opening system for high-rise DSF buildings. Detailed Computational Fluid Dynamics (CFD) simulation was used to develop an automatic opening pattern which was individually operated to optimize thermal character of the cavity.

Conceptual estimating in the proposal development is nontrivial and continues to be challenged by quality- and efficiency-related issues. As a remedy, parametric estimating is widely used. Despite the merits obtained, human involvement is always missing from the decision-making process. Information can hardly flow between different sources of opinions. This paper introduces an innovative paradigm that combines the intelligence of human beings and computational ability of computers. It smoothes the information flow in the mixture of human-network and computer-network, solicits and conserves knowledge and experience of estimators in the proposal development. A tool based on the proposed paradigm is developed named Interactive Parametric Estimating Tool (iPET). iPET was tested in the proposal development of a power plant project. Results show that the proposed paradigm enables fast and intelligent collaborative solution-seeking between estimators and computers while highlighting the role of estimators. This work offers a unique perspective to the estimators to envision and refine their work.

Open standards for infrastructure based on Industry Foundation Classes (IFC) are mainly developed by the open INFRA initiative of the building Smart organization. Recently, several proposals for alignment models emerged with the development of the upcoming IFC 5 standard that, in particular, targets infrastructure projects such as roads, bridges and tunnel buildings. A common drawback of all of these proposals is their limited description of arbitrary transition curves. For instance, in all proposed alignment models, there are some missing types of transition curves or different parameters are suggested to describe a certain transition curve type. Designing a neutral data format that satisfies all stakeholders in an international context is, therefore, difficult. A novel approach to describe transition curves based on the Industry Foundation Classes Programming Language (IFCPL) is described and its integration into an IFC-based alignment model is shown to avoid these problems.

Structure from Motion (SfM) is a well-known approach for extracting the 3D geometry of a structure from 2D images. Despite being inexpensive, simple, and automatic, it has not been widely used in the construction industry, mainly due to challenges in detecting and matching visual features. In built infrastructure scenes, most areas lack distinctive points due to the prevalence of poorly-textured surfaces which obstructs the successful use of SfM. In contrast, an abundant number of straight lines are visible but cannot be fully exploited because of the low performance of existing line-matching algorithms. When applied to infrastructure scenes, such algorithms produce many mismatches because of inaccurate locations of line end-points, fragmented lines, lack of geometric constraints, and lack of distinctive texture in the local neighborhood. This paper presents a novel method for tackling this problem. The key innovations of the proposed method are the joint use of local and global information in the scene and the canonical form representation of the support region of each feature. Using the scale-space theory, lines that are stable with respect to scale variations are first extracted. A dynamic pixel support region is then assigned to each line based on the Laplacian function. Each region is described by an affine-invariant vector. Finally, the Euclidean distance between vectors and global geometric constraints in the scene are applied to determine corresponding pairs. Experimental analyses have shown performance improvement compared to the state-of-the-art algorithms.

Nowadays, precast concrete panels are one of the most popular construction components. To safeguard the overall quality of construction projects, it is important to ensure that the dimensional quality of precast concretes conform to the design specifications. In order to achieve this, a terrestrial laser scanning (TLS)-based automated dimensional quality assessment technique has been developed by the author's group. The scope of this paper is such that the developed dimensional quality assessment technique is further advanced so that this technique can also be applied to full-scale precast concrete panels with complex geometries. A full-scale precast slab with dimensions of 10,610 mmχ1,980 mm in a precast manufacturing company is used as a test target to validate the effectiveness of the dimensional quality assessment technique. The challenges encountered during the data analysis of the full-scale test are investigated and resolved using optimized algorithms. Furthermore, comparison of the effectiveness between the conventional technique (deviation analysis) and the proposed technique is conducted. The average dimensional error for the proposed technique is 5.2 mm, while that of the conventional deviation analysis is 10.2 mm, demonstrating that the proposed technique can have high potentials in estimating and assessing the dimensional properties of the precast concrete panel

The prevalent method of measuring progress is through manual site surveys. These surveys are tedious and time-consuming. They are also approximate, as counting the number of bricks in-place to compare against those ordered is a very laborious task compared to its end value. In previous research, the authors were able to count the number of bricks using single images. This paper presents a novel method for counting bricks in-placed to automate the brick site survey using digital videos. This method improves the brick counting method on image to a continuous counting in video frames. It can compare the brick detection results in successive frames and accumulate the counts when new bricks appear. The method works by the following two steps: (1) count the number of bricks on the brick façade on a single video frame, and (2) track the detected bricks with a kernel-based tracking approach to compare the difference in successive video frames to avoid double counting, and add new bricks to the count upon the appearance in the successive video frames. This paper also demonstrated a performance comparison of the kernel-based tracking approach and point-based tracking approach. Test results demonstrate that this method is capable of counting the number of bricks on a brick façade with acceptable error.

Continuous condition monitoring and inspection of under-construction highway retaining walls is essential to ensure that construction performance criteria are met. The use of LIDAR systems by the construction industry has been significantly increased in recent years, especially for recording the as-built and as-is conditions of facilities. The high-precision, dense 3-D point clouds generated by 3-D laser scanners can facilitate the process of Asset Condition Assessment (ACA). ACA involves preprocessing the point cloud data, for which point clouds have to be cleaned of any unwanted or occluding objects and noises. As part of this research, the retaining wall point cloud data from an ongoing highway construction project was processed and analyzed. The project uses 3-D laser scanners for regular monitoring of mechanically stabilized earth walls that retain the soil supporting the highway alignment. The temporary steel and wooden brackets that hold formworks on top of the walls along with other construction materials are defined as unwanted objects. The authors have used a non-deterministic algorithm to remove the brackets and noises from the point clouds. Various settings of the algorithm have been analyzed using different sets of data. This paper presents the accuracy and performance of the tested algorithm and its evaluation when comparing the results with manually cleaned point clouds.

Given work is dedicated to study theoretical bases development of the method, which will allow to build the process of searching for the optimum management decisions, based on formalizations and automations deductive conclusion with reference to the management of such a complex system as construction. The Base of this method is semiotic modeling, i.e. a logician-linguistically approach of searching for of the decisions on management. The Construction(S) present sit self collection technical (T), social (C) and economic (E) of the systems. As a result, such a complex approach to production given problems is found algorithm of the building to management model to building organization with the use of logician-analytical methods of the quantitative analysis. The Article is dedicated to the development of models of construction management as bases for the maintenance of the normal move production provided that it is provided periodically and stability, the further development production with provision for use technical and technological innovation that will allow to raise the quality to product construction.

Safety continues to be among the top issues in the construction industry after experiencing 775 fatalities in 2012. Among all those fatalities, falling has been considered as one of the leading contributors for several years. This paper presents a method that automatically identifies fall risks on construction sites under excavation by utilizing laser scanning technology. It first extracts safety rules that are related to fall risks from OHSA standards and construction best practices. Then, it collects sets of point cloud data of a construction site under excavation using laser scanning, registering and cleaning the point cloud data afterwards. Finally, it develops an identification algorithm based on those rules and applies the algorithm onto the data to identify potential fall risks by analyzing geometrical properties. An experimental trial is also conducted in this paper and results show that the method successfully identifies those fall risks. The presented method can actively monitor the fast changing situations of construction sites under excavation and provide inspectors and project managers with valuable information about fall risks, helping them make good safety decisions and prevent fall accidents and fatalities.

Struck-by accidents are one of the major causes of fatalities in construction projects. The dynamic and complex nature of construction sites leads to layouts and motions that increase the vulnerability of workers and equipment to struck-by accidents. In this paper, we present our initial efforts towards a methodology based on information spaces for predictive assessment and proactive monitoring of struck-by safety hazards in construction sites. Our working hypothesis is that struck-by accidents occur due to undesirable states and trajectories in the physical state space that can be partially predicted and monitored in real time through efficient and robust algorithms. Our methodology includes multiple steps related to defining the physical state space and information spaces to compute filters for detecting hazardous states. In order to illustrate our methodology, we present three case studies of construction safety monitoring tasks related to: (1) worker-equipment collision avoidance; (2) falling/swinging load collision avoidance; and (3) distribution of workers in hazardous regions.

Falling from height is the top cause of injuries and fatalities in the construction industry. Understanding the fall risk at different work environment scan help to prevent fall accidents on a jobsite. While many previous studies attempted to assess the fall risk on a construction site, most of them are qualitative or subject to cognitive biases. In this context, this paper aims to introduce and validate a quantitative measure that allows researchers to characterize the fall risks of construction workers. In particular, this paper focuses on validating the fall risk predictive power of Maximum Lyapunov exponent (Max LE), which is one of the gait-stability metrics established in clinical settings. The kinematic data were collected using an inertial measurement unit (IMU) sensor attached to the right ankle of the subject performing different tasks. The Max LE for each tasks were then calculated based upon the IMU measurements. The results indicated a significant difference in the Max LE between different tasks, which indicates that Max LE has the potential to evaluate the dynamic stability of construction workers.

In the labor-intensive construction industry, workers are frequently exposed to manual handling tasks involving forceful exertions and awkward postures. As a result, construction workers are at about a 16 percent higher risk of work-related musculoskeletal disorders (WMSDs) than workers in other industries. A biomechanical model-based musculoskeletal stress analysis is one of the widely used methods to identify the risk of WMSDs during occupational tasks. However, the use of biomechanical analysis has been limited to only laboratory experiments due to the difficulty of collecting motion data required for biomechanical models under real conditions. To reflect postural variations when performing construction tasks, an effective and easily accessible mean that enables us to conduct biomechanical analysis under real conditions is required. To address this issue, we propose a motion-data-driven biomechanical analysis by enabling automatic processes to convert motion data from vision-based motion capture into available data for representing motions in biomechanical analysis tools. We conduct a case study on masonry work to determine the feasibility of the proposed method. The results show that the proposed approach has the potential to assess an individual's motions and to provide personalized feedback for the purpose of reducing biomechanical loads and WMSD risk in real workplaces.

Construction is generally conducted in highly changeable site conditions due to operation of machinery, transfer of materials, moving workers, and changing progress status. Such dynamic characteristics can always lend themselves to the potential for safety accidents. However, it is not easy to have a generalized safety management system that can universally apply to every job site. Although there are some guidelines for safety management, their application to a construction site has to be tailored to satisfy the unique nature of the particular project. Based on the good understanding of the particular site, effective and appropriate safety management process should be derived for workers to be protected from potential dangers of the site. This paper presents an on-site safety management methodology based on image processing and fuzzy inference. Image processing is used to extract spatial information of workers; fuzzy inference is then used to provide the workers a proper level of safety warning based on the spatial information. Contextual site information, such as equipment operations and density of workers, also constitutes the on-site safety management methodology. The proposed methodology is expected to provide a safer working environment for construction workers through its capability to easily customize the safety management system for a construction site.

Scheduling software used for construction projects is generally designed to plan and monitor activities and resources. These types of software allocate resources to the different activities and allow for resource levelling, costing and cash flow calculations. These features are well-adapted to subcontractors who manage their own human and material resource, and allocate them to the activities of one or a multitude of projects. General contractors and consultants do not generally have full control over project resources and, therefore, most software does not directly address their needs for monitoring unit- or fixed-price contracts. In addition, subcontractors' schedule structures do not necessarily follow the logic of the Bill of Quantities which makes it more difficult to monitor financial progress and cash flow. This paper exposes the problems and limitations associated with the existing scheduling software and presents three scheduling solutions using MS-Project and Excel individually or in combination. These methods have been applied to several case studies in irrigation and fisheries mega-infrastructure projects in Morocco and Burkina Faso. The methodology and proposed solutions are validated through their applications on these mega-projects.

Probabilistic simulation is a popular approach to analyze uncertainties in theArchitecture, Engineering and Construction (AEC) Industry, including Monte Carlo simulations of cost, PERT simulations, and probabilistic risk assessment. However, the application inefficiencies in the simulation process make it susceptible to problems of collaborativity, usability, and difficulties in interactive decision-making. This paper proposes a Cloud-based apparatus to improve the efficiency, usability, and collaborativity of probabilistic simulation in tacking a range of AEC problems using a Real-time Interactive Simulation Kit (RISK) tool. This tool may ultimately lead to interactive probabilistic simulation, which ensures a seamless integration between simulation and the decision-making process. A simulation technology called "Simulate As You Operate" (SAYO) was developed to realize a "What You See Is What You Get" (WYSIWYG) type of probabilistic simulation. The paper also includes two RISK applications - PERT simulation and risk analysis - to illustrate the tool. RISK presents an effective analysis and communication tool for the uncertainty analysis of AEC problems.

The construction environment affects workers' physical responses as well as individual and crew-level performance. Previous research has analyzed the relationship between worker performance and severe environments. This paper reports initial results and a process for establishing reliable, physiologically acceptable bounds and heart rate (HR) zones for construction workers. Five workers at the same building jobsite agreed to wear a Physiological Status Monitoring (PSM) system for several days while at work. HR data were collected to identify physiologically acceptable bounds and HR zones as practical threshold-based guidelines in construction. Since HR is affected by various external variables, daily video recordings and weather data were also collected and used to explain results.

Construction material supply on schedule is an indispensable factor for task operation and accomplishment of a successful construction project. Material flow in construction project, horizontal and vertical move and stand-by in the temporary storage, is able to incur the impact on the construction schedule. However, despite the material flow consisting of various tasks using plenty of construction resources (e.g. space, time, labor and equipment), the tasks concerning material flow have been excluded from the management domain of scheduling methods. In a super-tall building construction project whose shape is vertically long and whose site is usually located at a congested urban area, the limited material storage space and insufficient hoisting equipment are applied as critical constraints on material delivery on schedule. The characteristics of super-tall building construction - such as multi-task operation, non-repetitive operation resulting from irregular building shape, and the interaction between schedule progress and material flow - make it hard to identify the behavior pattern of material flow and to make an appropriate plan. These uncertainties remain as a critical risk and incur a schedule delay. This study aims to propose multi-method simulation model incorporating discrete event method and agent-based method in order to understand the complexity of material flow under the various constraints in super-tall building project and also to propose an optimizing model on ordering amount and time to prevent construction delay.

This study aims to eliminate the labor-intensive target installation process and its associated costs and other issues commonly caused from the current practices of laser based as-built data collection and modeling process. In this study, a laser scan system was utilized with corresponding texture data simultaneously obtained from a digital camera. Based on identified common features in the texture data, an optimized transformation matrix for the point clouds is generated. Then, the point clouds are registered without using any physical external target. The proposed method was tested at an on-going building construction project. The interrelationships among registration speed, registered accuracy, and size of overlapping area were examined. The field experimental results demonstrate that the proposed target-free geometric data registration method can significantly reduce the registration time without compromising the registration accuracy, thus simplifying and promoting the current laser scanning and registration processes for progressive as-built modeling of construction projects.

A 5-step method for developing configurable "products in product" platforms to be used in an engineer-to-order (ETO) design process is proposed. The idea is based on the transformation of typical product architectures into modular design platforms where standard and variant modules are identified and developed. The platform modules can then be configured and combined using traditional design methods to meet the project-specific requirements in the design process. Based on 1193 project designs, several configurable "products in product" were identified and developed in a real case study using the proposed method.

Research prototypes for Jobsite sensing are often developed for a particular scenario and address one or more domain-specific challenges using one or more of the sensor choices. However, numerous operational challenges remain and are a barrier to widespread adoption of sensing technologies. Choices made during the sensor deployment process have a huge impact on the information generated from sensor data. Consequently, the deployment choices impact the decision-making process that is supported by the information. This paper revisits the concept of a work space and redefines it as a basic unit of job site management from the sensing perspective. A set of parameters is proposed that can help managers in effective planning and control of sensing on jobsites. A case example is presented to identify sensing requirements for heat stress management on a jobsite.

The Australian construction industry is identified as one among five industries to receive priority attention under the Australian Work Health and Safety Strategy 2012-2022. Among the recorded construction fatalities in 2012, vehicle incidents accounted for 15% and being hit by moving objects accounted for 10%. Tracking of individuals on-site could provide a technological solution to improve safety. This paper proposes a novel, non-tagging-based, wireless networking solution (called device-free localization) to enhance safety on site. Device free localization techniques use radio signal propagation effects such as multi-path fading and shadowing caused by the obstruction(s). The proposed solution defines zones in the construction site. Zone identification is based on the risk associated with the location map of the site. Defining risk profiles considers the activities associated with the geographic location, such as loading/unloading areas, truck, and vehicle entering area. The presence of workers entering a particular zone is detected based on this device-free detection technique, which will later be extended to localization. This paper proposes a framework for defining risk-associated zones for the construction sites for the effective implementation of device-free detection systems. Feasibility of the proposed device-free detection technique is verified by preliminary experiments done in an indoor environment with high multi-path fading.

Emerging wireless sensing technologies hold great promise for improving construction resource tracking operations. Unfortunately, the accuracy and reliability of these sensing technologies, as well as their interactions with the dynamics of the construction environment, are still not well understood. Existing deployments of these sensing technologies are based on isolated tracking applications rather than adaptive interaction with the construction process. This adaptive interaction can be enhanced using Chirp Spread Spectrum-based swarm sensing systems capable of triggering collective and organized behavior amongst construction resources, a key characteristic of cyber-physical systems. This paper presents an experimental investigation of the performance of a commercially available swarm-sensing system on the construction site. This sensing system consists of sensors capable of interacting and communicating with each other without the need for stationary transceivers. A case study is presented to demonstrate the benefits and functionality of the sensing system. The results show that Chirp Spread Spectrum-based swarm sensing systems offer tremendous opportunity for future cyber-physical systems applications in the construction industry.

Marker-less motion capture has been extensively studied in recent years as a means of evaluating productivity, safety, and workplace design for manual operations on-site. These technologies are ideal for circumstances in which traditional motion capture systems are ineffective due to the need for a laboratory setting and movement-inhibiting markers or sensors. However, many marker-less motion capture systems rely on RGB-D sensors that have limited range and susceptibility to interference from sunlight and ferromagnetic radiation, making them unsuitable for modeling worker actions on construction sites. To address this issue, we propose a marker-less motion capture approach utilizing optical images and depth data obtained from stereo vision cameras. Multiple camera lenses and triangulation algorithms generate depths maps similar to those produced by RGB-D sensors, while still utilizing an optical recording process unhindered by potentially harsh construction site conditions. These data are adapted for existing kinematic modeling systems (i.e. iPiMocap Studio) for 3-D pose estimation. The experiments show that the proposed approach can provide data precision comparable to that of RGB-D-based systems with fewer operational constraints; thus, motion data can be collected where previously developed methods fail due to environmental or maneuverability restrictions. With the proposed approach, kinematic modeling of human movements can be carried out on construction sites without inhibiting the mobility of the recorded subject.

In projects with a tight schedule, one common approach to accelerate the construction progress is to work two shifts (i.e., daytime and night time). However, due to physical, mental and visual fatigue at night and changes in the working conditions as well as a lack of a sufficient number of supervisors at site, lower productivity rates are observed between day and night shifts. To achieve the planned productivity level at both shifts, an effective monitoring and controlling approach is needed. Field data capture technologies, such as RFID video cameras, are promising technologies in improving current control and monitoring approaches. However, some of these technologies are disadvantageous in monitoring construction activities under nighttime conditions. In this paper, performance of the field data capture technologies for monitoring and managing double-shift projects were evaluated by reviewing previous studies and an envisioned approach for monitoring double-shift projects by using the selected technologies were provided.

Construction companies in Hong Kong suffer huge losses due to labor fatalities and injuries. More than 25% of all of the injuries and fatalities in all industries in Hong Kong are caused by the construction industry. This is different from the U.S., whose top injury cause for fatal injuries is a fall to a lower level (34%) and nonfatal injuries (23%). The most frequent type of injuries in Hong Kong is due to lifting and carrying (19.2%). Recently, automated 3D sensing systems (Kinect) have been employed to identify motion-related hazards to improve construction safety conditions. However, limitations (such as extreme light conditions, occlusions and misrepresentations) of 3D sensing systems hinder its application in engineering practices. To resolve those limitations, this research proposed a coupled system which integrates and synchronizes the Kinect with Inertial Measurement Unit (IMUs). With the help of the coupled system, IMUs could uninterruptedly collect motion data (accelerations and angular rates), even under extreme light conditions or under occlusions, while Kinect could provide a reference system for IMUs to construct postures. The whole sensor network will be able to capture complete and reliable data even if Kinect fails to work properly. Moreover, the proposed coupled system will also promote other human related research, such as productivity and labor tracking.

In this paper, an integrated framework and a smart algorithm for vehicle positioning are proposed. The standalone Global Positioning System (GPS) cannot provide accurate location information in dense and indoor environments. Therefore, an integrated framework is proposed which exploits additional positioning technologies - including vehicle-to-infrastructure and vehicle-to-vehicle communications, radio-frequency identification, map-matching, and dead reckoning - for vehicle localization. Since different applications require different location accuracy, a smart algorithm is also provided which shows how different localization technologies under various situations are selected and used to obtain the desired accuracy with the least amount of complexity. A series of comprehensive MATLAB simulations are conducted to evaluate the performance of the algorithms. Simulation results show that: (1) standalone GPS is not a reliable positioning technique in all situations; (2) an integrated technique using several positioning technologies is required to achieve the minimum application requirements in all situations; and (3) using the smart algorithm, the required accuracy and latency can be achieved by selectively adding or removing localization resources.

Bridge load testing is generally used to evaluate the bridge's actual load capacity when the bridge has just been finished, repaired or retrofitted. Before carrying out the test, it is necessary to calculate the stress and displacement of observation points on specific sections of the bridge. During this process, the accuracy of the calculation and the convenience of the report output are of great importance. However, the existing software, which requires experts to deal with the huge task of preparing data and picking up results, is not so easy to handle. Moreover, sometimes even experienced experts cannot easily determine the exact positions of critical cross-sections in the bridge model. These problems may lead to an inaccurate result and, thus, more troublesome work. Considering the fact that new Load Testing Specifications for Highway Bridges (LTSHB) is about to be published in China, we have developed the software Bridge Loading Test analysis system (BLT) in order to provide experts with a better understanding of the new specifications and enable them to conduct bridge load testing more conveniently. This paper introduces the key module of BLT compiled with VB.net, which is easy and convenient to use.

Current safety warning systems generally operate based on the information from sensors attached to individual vehicles. This vehicle sensor-based system can only estimate the collision potential situation in close proximity of a subject vehicle, and it requires additional communication technologies such as Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication technologies in order to obtain a wide range of information. The device requirements for such technologies will lead to the price increase of the collision warning system. So, in this study, we propose the collision warning system that utilizes the information from the fusion of loop detector data and smartphone data. The proposed collision warning system can be directly applied without any additional cost because the databases of loop detector and smartphones are available to be used. The developed system is tested by simulating a real vehicle trip based on the NGSIM data and comparing its results to vehicle-sensor-based system and infrastructure information-based system. It was found that the newly proposed collision risk warning system can show the similar performance with the V2V-based collision warning system.

Commercial buildings show large discrepancies between estimated and actual energy consumption levels. Important challenges specifically lay in understanding the influence of human actions (by occupants and facility managers) on energy use and their contribution to commonly observed high energy consumption levels. This is particularly relevant in energy-intensive buildings, such as laboratory facilities, which can typically consume up to five times more energy than other types of commercial buildings. This paper presents a framework to (1) collect relevant data about building energy performance and occupancy, (2) mine data, and (3) adapt and use energy analysis methods to understand the influence of occupants on energy performance, detect inefficiencies in the operation of building systems, and propose solutions. The framework is illustrated though a case study on a laboratory building in Madison, WI, identifying an excess of 40 percent in the energy consumption of the Heating, Ventilation and Air Conditioning System (HVAC).

Opportunities for improving energy efficiency can be recognized in many different ways. Energy benchmarking is a critical step of building retrofit projects because it provides baseline energy information that could help building stakeholders identify energy performance, understand energy requirements, and prioritize potential retrofit opportunities. Sub-metering is one of the important energy benchmarking options for owners of aging commercial buildings in order to obtain critical energy information and develop an energy baseline model. However, it oftentimes lacks baseline energy models collecting granular energy information. This paper discusses the implementation of cost-effective energy baseline models supported by wireless sensor networks and Building Information Modeling (BIM). The research team focused on integrating the theories and technologies of BIM, wireless sensor networks, and energy simulations that can be employed and adopted in building retrofit practices. The research activities conducted in this project provide an understanding of the current status and investigate the potentials of the system that would impact the future implementation. The result from a proof of concept project is summarized in order to demonstrate the effectiveness of the proposed system.

To cope with a large disaster such as that caused by a large earthquake, it is necessary to gather seismic information and building damage data. This paper describes open source hardware (OSHW) with various sensors and a wireless communication system used as a new device to measure the strength of an earthquake and the extent of building damage. The OSHW assessed in this study is inexpensive and readily accessible. Therefore, the spread of wireless sensor network with the OSHW is expected. For this study, an acceleration sensor is used to conduct the following examinations. First, a component of OSHW with the wireless sensor network is explained, as are its specifications. Secondly, simple and extensive applications for the system for gathering seismic information and building damage data are proposed. Thirdly, future subjects of these applications are defined. Several fundamental test results are presented. Finally, the effectiveness of this seismic information gathering system is discussed.

To leverage all the benefits that building information modeling (BIM) is bringing to the built environment, the AEC industry recognized the critical need for BIM standardization. The issues of level of details and interoperability as means to communicate and integrate various model-based applications into an efficient workflow have materialized to the forefront of the standardization process. The ultimate goal of BIM standard is, in part, to enable capturing all relevant data in the BIM model, and to allow for flawless data exchange between the various applications. Current BIM tools that have been developed to model conventional structural steel and concrete construction are not yet satisfactory for modeling tensile structures. This paper reviews the current state of BIM platforms in modeling tensile structures and formulates the functional requirements for cross-platform standardization and interoperability. This study centers on advancing standardization of BIM models for designing and analyzing tensile structures. Specifically, the study addresses the Information Delivery Manual (IDM) and Model View Definitions (MVDs) as they aim to provide the integrated reference for process and data required by identifying the distinct processes undertaken to design tensile structures as well as to create an efficient method for unified, reproducible exchange of consistent information that is customarily acknowledged by the industry.

Tensegrity structures are sensitive to wind. Wind-induced dynamic analysis for arched tensegrity structure is performed with the nonlinear random simulation method in time domain in this paper. Several parameters - such as wind speed, length-width ratio, rise-span ratio and prestress of cable - are considered. The arched tensegrity structure appears obviously peak resonance in the low-frequency part under wind load. Reducing the length-width ratio and increasing prestress can reduce wind-induced response of the arched tensegrity structure effectively.

The prediction of seismic damage to buildings in urban areas is an important technique for the mitigation and prevention of earthquake-induced destruction. A methodology is proposed for such predictions. It is based on high-performance graphics processing unit (GPU) computing, which is applied to a case study of a real university campus. Specifically, an overall framework is designed based on cooperation between the GPU and CPU. A high-fidelity structural model suitable for GPU computing is built and the thread structure of the GPU-based seismic damage prediction is discussed. Taking Tsinghua University campus as an example, the seismic damage to the entire campus is predicted efficiently by the proposed method, and the detail of local damage on different stories is obtained explicitly. Furthermore, an increase in speed of approximately 21 times is achieved in comparison with a traditional CPU approach. The outcome of this study provides a critically important reference for the prevention and mitigation of urban disaster.

Reinforced concrete (RC) shear walls is one of the most widely used lateral force-resisting members of high-rise buildings. This research developed a multi-layer shell element on an open-source FE code of OpenSees for shear walls. The multi-layer shell element can simulate the coupled in-plane/out-of-plane bending as well as the in-plane shear and coupled bending-shear behavior of RC shear walls, and it comprehensively reflects the spatial mechanical behavior of the shell structures. The simulation of rectangular walls, flanged walls and coupled walls under pseudo-static loading was conducted. The simulated results agree well with the experimental results, which validates the rationality and reliability of the proposed model. The nonlinear seismic analyses of a super-tall building - namely, Shanghai Tower with a height of 632 m - were conducted based on the fiber beam and multi-layer shell elements. Good agreement was achieved between the analytical results of OpenSees and MSC.Marc. The outcome of this study provides an effective tool and a useful reference for the simulation of high-rise buildings using OpenSees.

In spite of many favorable characteristics of guided-waves for Nondestructive Evaluation (NDE) of pipes, real-world application of these systems is still quite limited. Beside the complexities derived from multi-modal, dispersive and multi-path characteristics of guided-waves, one of the main challenges in guided-wave based NDE of pipelines is sensitivity of these systems to variations of environmental and operational conditions (EOC). This paper investigates the effects of varying EOCs on guilded-wave based NDE of pipelines. We first provide a review of the studies to date in the field of guided-wave based testing to identify research gaps for enhancing the application of these systems in pipeline NDE. To study the identified gaps, guided-wave data from a fully operational piping system, with continuously varying flow rate and temperature, is used. Time-shift and amplitude drift effects due to flow rate variations are evaluated along with those of temperature. It is observed that masking effects of flow rate for damage detection can be at least as significant as temperature effects, and that such effects become more dominant when flow rate and temperature variations co-occur.

Temporary structures, such as formwork support and scaffolding, play an important role in on-site production for construction projects. However, they are normally disregarded when considering the importance of qualifications and experience. In fact, most of the time, temporary structures won't be considered until it is actually constructed. As a result, most tragic failures during construction are usually the result of improperly designed, constructed and/or maintained temporary structures. A real-time monitoring system enabled by video cameras may facilitate the monitoring of integrity and safety of construction temporary structures. It entails applying close-range photogrammetry and digital image correlation to measure the deformation of structural material shapes. In this system, stereo image matching algorithms and accuracies are considered to be one of the most significant elements. It is to seek the corresponding relationships between left and right-view images of the same scene to obtain the disparity images. Thus, this paper attempts to evaluate the image matching algorithms that exist in order to identify the most appropriate one for the temporary structure monitoring system. First, the principle of stereo matching is introduced. This is followed by the comparison of three classical algorithms, semi-global matching (SGM), block matching (BM), and graph cuts (GC) method. The undertaking of the comparison includes statistical analyses of the time and disparity images quality estimation. The research concludes that the SGM algorithm possesses both relative high efficiency and disparity images with excellent qualities. The present work facilitates the investigation of the aforementioned monitoring system.

Taishan nuclear power plant is the third one under construction of European Pressurized Reactor (EPR). To more accurately simulate hydration temperature field in the slab of Taishan nuclear power plant unit 2, the Equivalent Age-Hydration Degree Curve (EAHDC) was developed and was used in combination with the Model Change Interaction Function (MCIF) of ABAQUS to consider effects of age, temperature and construction process on hydration thermal field of concrete. Given the characteristics of construction process and geometry of the slab, a half model was adopted to predict hydration temperature field of the whole slab, and MCIF was used to simulate the construction process. With combination of EAHDC and MCIF, the thermal properties of concrete were practically defined as a function of age, temperature, and construction process. Compared with the onsite measured temperature and the simulation temperature without consideration of construction process, the EAHDC-MCIF combination method provides improved accuracy in the simulation of hydration temperature field of concrete.

A central component of every decision support system is a performance prediction model. Often, empirical data is used to describe a performance measure as a function of factors affecting performance. In this context, hosts of machine learning techniques have demonstrated function approximation capabilities beyond regression methods. This study is aimed at comprehensive comparison of nine machines learning algorithms for developing a pavement performance model. Instrumental in pavement management systems, this extensive evaluation reconciles computational intelligence with systems engineering. Three principles of maximum likelihood, consistency, and parsimony are considered in algorithm benchmarking and model development. Along with quantitative measures of accuracy and generalization, qualitative criteria - including scatter plots and sensitivity analysis - are also implemented. Additionally, quantitative and qualitative aspects of model evaluation are combined through analysis of predicted performance trends. Results indicate that an algorithm performing the best in each comparison step might not achieve the same in the other. This comparison framework is recommended for identifying the appropriate machine learning paradigm to develop performance prediction models.

High-intensity rainfall of short duration is triggered by mesoscale convective clouds and remains difficult to forecast with numerical forecasting models. The Water Resource Agency (WRA) in Taiwan has developed a flood alert system that has defined two levels of flood warning based on predefined rainfall thresholds in each township. The system tracks rainfall in real-time through rain gauge stations in specific locations and then issues flood warnings to the corresponding affected townships when the rainfall reaches a predefined threshold. However, the system does not account for temporal-spatial rainfall distribution and the density of rain gauge stations; because of failed alarms that can thus result, some townships are inundated during the heavy rain and typhoon season. To improve the effectiveness of the flood warning system, we have proposed a methodology utilizing data from Quantitative Precipitation Forecasts (QPFs) to examine and revise the rainfall thresholds of the WRA. This procedure has two phases: (1) assess the effectiveness of flood warnings in each township, and (2) adjust the original rainfall thresholds. Taking New Taipei City as the study case, we revised the rainfall thresholds in five townships based on the proposed methodology and rainfall data collected during the invasion of Typhoon SAOLA that attacked Taiwan from July 31 to August 3, 2012. The revised thresholds will be tested in future events to validate their effectiveness with regard to accurate flood warnings.

Computational methods have been successfully applied in structural analysis and drawings of large spatial structures. However, there are still huge challenges in performing conceptual design of structures using computers for what the human brain is able to do. A computational method, named performance-based structural synthesis, has been proposed and validated to generate and realize planar truss structures. However, it is insufficient for more general spatial truss structures whose geometries and load-carrying requirements are more complex compared with those of a planar truss. Therefore, this computational synthesis method based on planar shape grammar was extended and presented in this paper to generate three-dimensional spatial truss structures through building 3D shape grammars and multi-objective hybridized optimization algorithm. Meanwhile, techniques of load-generation were employed in the structural synthesis method to realize its engineering application. In the aspect of structural configuration, the method integrates structural topology, geometry and section size allocation. In the aspect of structural design and optimization, it takes into account the combining effects of safety, economy, construction and architectural elegance. Thus, the structure generated by this synthesis method must be the best design in terms of the overall structural performance and cost compared with that obtained by the traditional design method.

Agent-based modeling (ABM) techniques have become another viable option for solving highway transportation problems. Research advancements in recent years have guided the possible integration between the ABM techniques and traffic simulations in addressing various transportation demand problems especially related to predicting road user behaviors. However, previous ABM simulation frameworks were implemented with a very high amount of modeling details (abstraction) to simulate microscopic vehicle movements and study real-time road user behaviors and responses. The application of the agent-based integrated traffic simulations at this level of abstraction may not be efficient for producing a more aggregate result required in the analysis of long-term transportation projects. In addition, very few ABM simulation frameworks have taken into account complex interactions between the supplied levels of service from a highway network and the aggregate demand created by road user choices. This research, therefore, proposes a model architecture and a theoretical framework for an agent-based traffic simulation at a mesoscopic level. In the framework, traffic simulation is created from an agent-based system where road user agents are interacting with one another and the highway network through network levels of service. The framework's model architecture is defined by two components including a highway network and user agents. The definition of this modeling architecture is targeted at utilizing the strength of the ABM techniques to address long-term transportation problems by providing an appropriate aggregate level of traffic simulations, while maintaining the ability to represent road user behaviors.

Genetic algorithms are techniques inspired by the mechanics of natural selection and genetics. They adopt survival of the fittest and structured exchange of information as basic mechanisms for optimization, and they are deemed suitable for construction site planning. Among the commonly-used multi-objective genetic algorithms, the Non-dominated Sorting Genetic Algorithm stands out as a robust optimization algorithm for such type of construction optimization problems. The main objective of this study is to investigate the performance of the algorithm under the alteration of optimization parameters. Specifically, the study investigates the performance of the algorithm under the variation of the population size, number of generations, type and value of cross-over probability, and mutation likelihood. This study should provide a better understanding of the behavior of the algorithm in solving site planning problems, and identify strategies that could help accelerate convergence toward optimal solutions.

Pseudo-static test of two groups of mild steel shear panel dampers (MSSPD) made of LYP160 steel were carried out for study of the mechanical properties, low cycle fatigue behavior and earthquake mitigation effect. Four groups of the loading history were applied to trace the hardening of the shear panels. The influences of web plate size and width-thickness ratio and the cyclical load amplitude were analyzed. The entity model was built by ANSYS with both geometric and material nonlinear analysis included in modeling. The combined hardening material model of Chaboche kinematic hardening rule and Voce isotropic hardening rule was adopted to simulate the cyclic hardening of LYP160 steel. The result shows that MSSPD has the features of large initial stiffness, high ultimate bearing capacity, favorable ductility and excellent energy dissipation capacity. The mechanic parameters are influenced by the sizes of the shear panel and the amplitude of the load history. Simulated hysteresis loops predicted by combined hardening model agree well with test results, especially reflecting the cyclic hardening character of low-yield-point steel.

War, terrorist attacks, explosions, progressive collapse and other unforeseen circumstances have damaged many buildings and bridges. Evidence from studying damaged structures has shown that Reinforced Concrete (RC) slabs, beams, and columns were damaged, but did not fail and can be strengthened using Carbon Fibre Reinforced Polymer (CFRP) to restore their load-carrying capacities and make them serviceable. Currently, there is no reliable analytical model that closely represents the true behaviour of the CFRP-strengthened elements. This study extends the research on the implementation of model updating techniques on RC beams, to RC beams strengthened with CFRP. Our research shows that it is possible to find analytical models that closely match the experimental results. These analytical models can be used to more accurately predict the behaviour of the damaged structural elements strengthened with CFRP.

This paper presents a reduced order finite element model for sound transmission analysis through a double-wall sandwich structure with viscoelastic core inserted in an infinite baffle. The proposed model is derived from a multi-field variational principle involving structural displacement and acoustic pressure inside the fluid cavity. To solve the vibro-acoustic problem, the plate displacements are expanded as a modal summation of the plate's eigen functions in vacuo. Similarly, the cavity pressure is expanded as a summation over the modes of the cavity with rigid boundaries. Then, an appropriate reduced-order model is introduced. The structure is excited by a plane wave at the source side. An example of the normal sound transmission loss of a double-glazed window with laminated glass is shown. This example illustrates the accuracy and the versatility of the proposed reduced order model, especially in terms of prediction of sound transmission.

Despite the fact that the semi-rigid nature of steel structure joints has been well-known for several decades, the truss design is constantly being carried out with ideally hinged joints in the finite element models. In some recent studies, the stiffness of welded tubular truss joints have been defined as well as the member buckling lengths in the trusses. The aim of this paper is to see the effects of applying the stiffness and buckling length knowledge in thetruss design procedure. By an example case, it is shown that joints can be treated almost ideally rigid and, in brace design, shorter values for buckling length could be used than those proposed by Eurocode standards.

During the assembly process of steel beams, the laborers must stand on narrow steel beams to assemble structures. Locating and bolting are two main steps in the steel beam assembly process. In the locating step, laborers haul and position the steel beam into the target position. In the bolting step, laborers assemble the steel beam with bolts. This manual assembly method can result in potentially fatal falling accidents. The efficiency of the process is also difficult to control. Therefore, we propose an autonomous joint system that will remove the need for laborers to work in elevated positions. The system consists of two subsystems: a steel beam hauling system and a bolting system. In this study, we focus on the design of the steel beam hauling system. The steel beam hauling system can catch the draft cable using an electromagnet and haul the lifted steel beam to the target position. The cooperation between the system and the tower crane is also considered. The system can be attached to each steel column before erection then removed by the tower crane after the assembly process is finished. The system was built in a scaled-experiment construction site to test its feasibility. In conclusion, we propose an autonomous joint system that can help reduce accidental falls and improve efficiency of the steel beam assembly process.

In testing the fibre-wrapped concrete specimens under compression, the failure of the GFRP wraps is observed at or near a corner in all the specimens, mainly due to stress concentration. This may be expected since the prism's sharp edges are not rounded off. In order to avoid stress concentration, an attempt is made to round off the sharp corners. To further study this problem, this research undertook compressive testing to investigate the effect of the corner radius on the strength and ductility of the FRP confined concrete prisms. This paper reports a series of tests on glass fiber-reinforced polymer (GFRP) confined concrete prisms. A total of twenty-three prisms of size 150 × 150 × 300 mm were tested under the strain control rate of loading. The primary variables in the investigation were the corner radius, transverse jacket, spacing of laterals and volume fraction of the polyolefin fibers. The results show that the smoothening of the edges of a square cross-section plays a significant role in delaying the rupture of the FRP composite at these edges, and the efficiency of the FRP confinement is directly related to the radius of the cross-section edges. Furthermore, it is revealed that the confinement provided by a jacket with rounded corner radius is not only increasing the strength of the concrete prisms, but significant in increasing the ductility of the concrete prisms.

Numerical stability and computational accuracy are required for the nonlinear full-process shear analysis of reinforced concrete (RC) structures and members. For this requirement, the planar membrane element is implemented and employed based on the rotating crack model. First, the complex plane stress conditions of RC members are classified into three groups of principle strain states in the principle strain space. Then, the computational methods for the three different principle strain states to update stress and calculate Jacobian Matrix are given. Third, the flowchart for programming is developed and the program of the planar membrane element is implemented based on the large generic finite element package, ABAQUS 6.9. Finally, tests of a group of classic RC beam and a series of typical RC shear wall are selected for the application and validation. Good agreement is found between the test and predicted curves and ultimate capacities. Comparison results also demonstrate that, by integrating the flowchart given in this paper into the program of the planar membrane element, good numerical stability and computational accuracy can be gained.

Along with hydrocarbon gas explosions and fire, objects dropped from cranes are one of the most hazardous events during the operation of the topside of offshore plants. Although it is strongly suggested by international rules and regulations to evaluate probabilistic impact risk from dropped objects in the offshore industry, most engineers have had difficulties in estimating a reliable risk value because there is no concrete guideline on probabilistic impact risk analysis. Therefore, an algorithm to compute a reasonable probability of structural failure is proposed in this paper. Nonlinear transient finite element structural analyses for a 3D pipeline protection system on a topside module are carried out using LS-DYNA in order to get structural responses for each of the selected dropped object scenarios.

To overcome the difficulty of integrating continuous/discontinuous numerical methods to a software and retain its flexibility at the same time, National Center for Research on Earthquake Engineering (NCREE) under National Applied Research Laboratories (NARL) in Taiwan has designed a Versatile Engineering Simulation ENvironment (named VESEN), which is a coupled continuous-discontinuous simulation platform based on Vector Form Intrinsic Finite Element (VFIFE) method and Discrete Element Method (DEM). Object-Oriented Programming (OOP) technology and design patterns in software engineering are used to facilitate VESEN's software usability and extensibility for adapting future requirement changes involving various constitutive laws, contact detection algorithms, geometric shapes of elements, interaction solvers, control points (in VFIFE method), and member sections. This paper presents the software framework of VESEN with a concept of "solver pool" and illustrates an iterative simulation procedure for ensuring the simulation consistency between rigid and deformable elements. Currently, VESEN has been successfully prototyped and tested in studying seismic behavior of bridge models with functional bearings. It can be expected that VESEN can address large-scale deformation and collapse of buildings and soil-structure interaction problems in the future.

The article discusses the need to use statistical methods of estimation and decision-making on operational reliability and durability of building structures and materials based on the accumulation of complete, continuous, reliable and uniform statistical information relating to the stages of development, implementation and maintenance of residential buildings.

While early days of structural analysis (and other engineering) software have been dominated by self-developed and self-maintained programs and applications, most of these tools have lately been abandoned in favor of out-of-the-box commercial software packages, usually due to the inability to cope with the advancements in the computer industry from both software and hardware perspectives. Even though the computational engines of these software tools and applications are still sound, the pre- and post-processors are outdated and not suitable for modern engineering use. On the other hand, the last decade offered simple, intuitive, effective and widely accessible services of the modern web resulting in the fusion of services blurring the boundaries between desktop computers, laptops and other consumer devices. Consequently, more and more applications are developed as web services move from the desktop environment to the browser. This paper presents the architecture, development and deployment of the web application framework that can transform console stand-alone tools into fully functional web applications. The framework was developed following the principles of the service-oriented architecture using cloud computing guidelines and the software-as-a-service model of deployment. The use of modern web programming principles and techniques provides the ability to use the framework on a wide range of consumer devices while the underlying high-performance/throughput computing system ensures scalability, flexibility and performance. Last but not least, two case applications utilizing the proposed framework are presented.

The main issues that significantly contribute to problems and delays on construction sites are changing client's view, incomplete design information, and poor site monitoring and control. Although experienced designers and construction managers control or minimize such problems during the design stage, the complexity and amount of the information in a pre-construction project makes such a task very difficult to accomplish effectively. This paper presents an actual case study model for an integrated system which aims at presenting construction activities in 3D using virtual reality. Firstly, the technology enables construction managers to walk through the proposed building, perhaps at different construction time intervals,-giving a vivid appreciation of the whole situation. Secondly, it enables the users to interrogate the building structural elements to present its details progress, thus giving a total virtual structural view of the project. Thirdly, the design effect of any changes in the building configuration can be modeled and visualized, and the cost effect can be calculated. Finally, the system enables virtual models to be shared and, thus, facilitates collaborative global design and construction.

The cable-stayed bridge with steel-concrete hybrid girders is one of the most widely used bridge types in China. As the key sub-structure of this kind of bridge, the hybrid zone - which consists of girders in the region jointing the steel girder and the concrete girder - plays an important role in securing the safety and good serviceability of the entire bridge. Consequently, the study on the mechanical behavior of the hybrid zone is essential for both the analysis and design of the whole bridge. However, due to the strong dependence of the Saint-Venant Principle and significant influence of the Fuzzy Region which cannot be quantitatively determined, the traditional local-elaborate modeling method for the study is limited by its dim Saint-Venant Region-Fuzzy Region boundary, leading to unreliable analysis results and enormous trial and error works. To tackle this problem, the multi-scale modeling method is introduced in this paper, employing the flexible boundary conditions (flexible BCs) for the simulation of the complex boundary condition of the hybrid zone. The fourth dimension is time. In order to gain results closer to the realistic behavior of the bridge at the finished date, it is considered to model the construction process. A 4D multi-scale model of the hybrid zone is then established according to the prototype of an actual cable-stayed bridge project in Chongqing, China. Simultaneously, a local-elaborate model is built for comparison. Comparison study of the finite element models demonstrates that analysis results of the 4D multi-scale model are reliable without the influence of the Fuzzy Region. The model is more accurate, reliable and, hence, widely applicable. It is concluded that the 4D multi-scale modeling method may offer a new approach for the analysis and monitor of the hybrid zone for cable-stayed bridges with steel-concrete hybrid girders in the future.

3D finite element (FE) analyses were carried out for 100-m and 400-m-high RC chimneys having piled annular raft and annular raft foundations considering the flexibility of soil subjected to across-wind load. Stiffness of supporting soil and foundation were varied to evaluate the significance of SSI. The integrated chimney-foundation-soil system was analysed by finite element software ANSYS based on direct method of SSI assuming linear elastic material behaviour. FE analyses were carried out for two cases of SSI, namely:(1) chimney with annular raft foundation, and (2) chimney with piled annular raft foundation. The responses in raft, such as bending moments and settlements, were evaluated for both cases and compared to those obtained from the conventional method of analysis of annular raft foundation. It is found that the responses in raft depend on the stiffness of the underlying soil and the stiffness of foundation.

In the design process, a virtual model, which can be called an information structure, is built up using information in a virtual space. The information structures used in construction are propagated as a design progresses. However, this process has not been sufficiently analyzed and optimized for computer-based design. This paper summarizes the concept of information propagation in the construction process and analyzes the information flow in the process of highway design. The analysis of the highway design process clarifies the problems with the conventional paper-based method of highway design. The systematic flow of a computer-based highway geometric design method is shown and the need for a paradigm shift in the highway design method and the relationships between designers, system developers, and verifiers are discussed.

Parameter or system identification is a useful tool in civil engineering. They have wide applications across many disciplines. However, due to the lack of general-purpose tools for such analyses, researchers need to develop their own codes with duplicated efforts. Yet, it is sometimes difficult to adopt other people's code due to different modeling methods used. Thus, there is a need for general-purpose tools to resolve problems of this kind. This paper describes a general-purpose system for such purpose. The system has three features. First, it uses cloud-computing technology to provide large-scale capabilities. Second, the system uses a JavaScript engine for developing extensions. Third, it employs multi-objective particle swarm optimization for its applicability on a wide range of problems. These features allow the systemtoprovide general capabilities to solve problems with similar needs. The design is validated and demonstrated by identifying constitutive model parameters in geotechnical engineering.

In the recent decade, the use of Personal Digital Assistants (PDAs) and smart phones had incredible growth and they can be used as a small computer in business, communication and education. Most of the current civil engineering software are created for desktop computers in specific operating systems and platforms without any portability and flexibility feature. This paper proposed a web-based architecture for an interactive Finite Element (FE) program. The architecture supports linear and nonlinear analysis of reinforced concrete buildings subjected to static and dynamic loading. Structure modeling is performed on the client-side via any internet browser. Data is sent to the server and analyzed by FE program which has been installed on the server. Then, the result of the analysis (which is the response of structure under imposed load) is sent back to the client-side to show and plot output of analysis. The developed software, which is named Analysis of Reinforced Concrete Structure (ARCS), is implemented in a secure and user-friendly interface. Running software in offline mode is possible for modeling, but internet connection is needed to transfer input data to the server and transfer output of analysis from server to the client-side. The most important advantage of the proposed model is the operating system and platform independency. Backup capability of all data and authority access control are other features of ARCS. Therefore, the developed software is able to be used extensively by engineers to carry out modeling and analysis of structures by any PDAs or smart phones through any operating systems and platforms.

Steel plate shear wall is one of the efficient and economical lateral resistance systems which has been implemented in various structures, located in highly seismic prone areas. Infill steel panel is surrounded by beams and columns as boundary elements, to provide sufficient lateral stiffness of structure. This study presents verification between prior studies and computer modeling of various structures equipped by steel shear walls based on the equivalent truss element method. Furthermore the efficiency of the aforementioned system is compared with special brace frame in terms of maximum displacement, base shear, axial force, rotation of critical columns and material usage by aid of time history analysis. The results show that existence of shear wall as a lateral resistance system decreases maximum displacement, base shear, axial force, torsion of critical columns about 25 %, 60%, 50% and 80% respectively, compared with structure equipped by special steel concentrically braced frame. Both systems passed the code requirements for maximum displacement, but application of steel plate shear wall reduced total weight of structural steel elements around 21%. Furthermore, results reveal that equivalent truss element is a reliable method for modeling shear wall element in computer modeling since results are verified by previous studies as well.

Cross-cultural interaction in global business has become standard in the design and construction industry. This paper presents lessons learned from a study aimed to determine how different multi-cultural team settings and cultural awareness trigger different conflict situations and influence team dynamics and processes. We build on extant classic mono-cultural studies and extend it to focus on analyzing the influence of different multicultural team settings on global project product and process success. We used empirical data from the 2012 generation of the 19^th AEC Global Teamwork course offered by the PBL Lab at Stanford with partners worldwide. We took an inductive approach, integrating qualitative and quantitative methods for date analysis. The paper presents cultural team compilation cases of AEC global student teams that were successful or challenged in producing high quality solutions and achieving effective team processes. The paper discusses findings related to: the relation between nationality and migration backgrounds indicating that mono-culture studies do not suffice to analyze global teamwork; correlation of project outcome and the multi-cultural team compilation; correlation of cultural awareness and diversity of global team processes towards successful multi-cultural team interaction.

An effective resource allocation technique is required for each Ready-Mixed Concrete (RMC). Finding the optimum solution for large-scale RMC dispatching problems with available computing facilities is intractable. Two kinds of techniques have been implemented to deal with this problem: (i) evolutionary techniques and (ii) numerical techniques. For the purposes of this paper, we selected a technique from each category and compared them under the same conditions. Robust Genetic Algorithm (Robust-GA) and Column Generation (CG) were selected and tested with different sizes of real RMC problems. The results show that, on average, CG solutions are obtained with a 20% reduced cost. However, Robust-GA converges 40% faster than CG, while the number of unassigned customers for both of the techniques is almost the same.

Corporate experience claims that the most efficient interactions are when all project stakeholders are collocated. This is extreme collaboration when people, content, models, and processes are collocated. Nevertheless, the AEC industry experiences a continuous increase in mobility, globalization, collaboration, digital content, interactivity, and convergence of physical and virtual workplaces. This paper presents transformative impacts on product, process, and interaction of immersive 3D virtual collaboration environment in support of global teamwork. The empirical data and findings are based on longitudinal studies performed over four years observing 24 cross-disciplinary, geographically distributed AEC student project teams in the AEC Global Teamwork education testbed. The deployment and adoption of agile, integrated, project delivery work practices facilitated by the immersive 3D virtual collaboration environment demonstrate innovative and effective new ways of working such as co-creation of collaboration spaces, content in context, experiencing and troubleshooting design and construction issues in the virtual BIM models.

A construction project in the public sector has additional complexity due to the number of disciplines and stakeholders with individual interests and different ways of expressing and interpreting information. The approach of collaboration helps to define common goals and commitment between the parties, and the Information and Communication Technology (ICT) acts as the support structure for relationships due to its characteristics to support communication, graphical representations and project development. This paper aims to apply a collaboration model supported by ICT in a building and infrastructure design process related to the public sector, listing the reasons why the parties collaborate and cooperate, the necessary structure and the ICT aspects that can provide support. The research method is exploratory in a case study fashion which consisted of a theoretical research to define the initial collaboration model framework adaptation and the field study to validate it. The case study was developed in a City Hall in the South of Brazil. The results present opportunities for reflection about the collaborative management of public projects and confirm that organizational and behavioral aspects are relevant to better understand the improvements generated by ICT use by public building design teams.

It has been recognized that building information modeling (BIM), as an emerging information communication and technology (ICT), can improve project collaboration to different extents. However, because of the fast progress of BIM adoption both on the scope and in depth, there is a knowledge gap between practice and theory that lack of systematic analysis on critical success factors (CSFs) of implementing BIM for collaboration in construction project. This paper develops a framework of BIM implementation for collaboration from technical, organizational, process and legal scopes, and identifies the CSFs of BIM in each scope based on the latest publications. From system analysis perspective, the pair-relationship matrix is established to reveal the hidden effect between CSFs. The CSFs in the specific BIM application areas are identified based on the matrix.

Cooperative processes are critical in complex projects involving stakeholders from different branches. The need to coordinate tasks and exchange information between production line and factory planning are key challenges for industrial plant construction management. Inefficient collaboration leads to increased cost and time, low quality, reduced output, loss of competitiveness and income and unfavorable image. This paper presents root causes of collaborative problems between production line and factory planning. The study integrates lean project management principles and root cause analysis methodology. This methodology is applied in a qualitative case study that builds on project data from production line and factory planning work environments, including the results of brainstorming sessions, online-survey and comparative analysis of industrial plant planning projects using different levels of lean project management ICT.

Fast project delivery is a common goal for all participants (owners, constructors, vendors, etc.) within the construction industry. Prefabrication is attractive because it offers an approach to complete construction projects within a much shorter duration than traditional construction methods (Retik 1994). However, the successful completion of prefabrication projects requires careful planning prior to implementation. The complex nature of prefabrication project scheduling makes traditional scheduling tools (CPM, PERT, Gantt charts, etc.) ineffective due to a common phenomenon termed "iteration". Iteration is a cyclic process and results from activity interdependency. Dependency Structure Matrix (DSM) is an alternative approach that has had much success in manufacturing, but has seen limited application in construction. It offsets the shortcomings of the traditional scheduling tools in dealing with the phenomenon of iteration. This paper first discusses the applicability of DSM to prefabrication projects. An example model that demonstrates the application of DSM is then developed and used to demonstrate determining an optimal schedule in terms of total feedback distance. To improve the accuracy of project duration estimations, the Reward Markov Chain method is employed to estimate durations of sequential iterations. In addition, an example of using the Reward Markov Chain method is demonstrated. The paper concludes with a discussion of the advantages and disadvantages of the approach.

Design, construction and operation of building heating, ventilation and air conditioning (HVAC) systems are complicated processes that generally involve several stakeholders, such as mechanical designers, control system integrators, commissioning agents and facilities managers. It is important for all these stakeholders, at various phases of the project, to have a thorough understanding of the system components as well as the control strategy according to the design intent of the mechanical designers. For example, when assessing the behavior of an HVAC system during operation phase, it is important for facilities managers to check for the correctness of every component's behavior and its control logic against the design specifications. The control sequences and logic of HVAC systems are primarily conveyed through schematic diagrams and textual descriptions called "sequence of operations" (SOOs) in construction documents (ASHRAE, 2004). Several challenges are associated with extracting and interpreting the information contained in these SOOs. Through a detailed analysis of a case-study conducted in relation to the information provided in the SOOs for the air handling unit (AHU) in a building, the research described in this paper highlights these challenges. Challenges such as missing information for controlled parameters, as well as textual descriptions that are open to interpretations, are common and result in inaccurate interpretation of the system behavior. This may adversely affect the overall performance of systems and lead to energy inefficiencies.

Improving productivity and innovation is a central challenge in all industries, but particularly in construction, where improvements have been slow. The Swedish Transportation Administration, the largest public client in Sweden, has launched a research and innovation program to increase productivity by fostering an industrial approach and identify ways to increase the standardization of products and processes. The use of customizable platforms in bridge construction is, in this paper, explored as a tool for increasing the standardization. The connection between the product and process platforms, especially, is exemplified using a developed bridge concept by a Swedish contractor. The development of modular platforms needs to consider which components and processes can be specified (standardized) in advance and which need to be uniquely adapted to the specific project. Also, the encapsulation of knowledge in standardized design and construction modules in supporting platforms and configuration tools turn tacit personal know-how into formal explicit knowledge that can be managed and continuously improved by the construction company.

In order to support a variety of commissioning processes in an automated way, differences and commonalities regarding information exchanges and data flows associated with the commissioning of different types of systems and components should be identified and formalized. In relation to this, we investigated the construction phase of an energy retrofit project in Philadelphia, PA. Specifically, we studied two systems that directly affect the energy consumption, occupant comfort and the operation costs of a facility: the Heating Ventilation and Air Conditioning (HVAC) system and the building envelope. First we identified tasks, stakeholders and required information exchanges. Then, comparing these information exchanges with the Model View Definition of the Industry Foundation Class schema, we analyzed whether these exchanges exist or have to be created to support the use of computational tools during commissioning processes. This paper summarizes our findings.

The progress of science and technology has been tremendous in the last two decades, especially in fields related to ICT. We, civil engineers, are adopting more computerized techniques for a growing variety of applications to increase construction efficiency. However, the historic industry reliance on manual paper records and/or non-integrated electronic systems for archiving has resulted in considerable useful data being lost. To address these issues the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has been introducing Civil Information Modeling (CIM) in the civil engineering field since 2012 to improve the efficiency and continuity of valuable construction data. In this paper, we carried out two surveys to explore and evaluate the relationship of the management elements defined by PMBOK so as to identify the critical issue associated with utilizing CIM in the civil engineering field. We employed a network analysis technique for numerical considerations.

Delay risk factors associated with clients have a major impact on the successful delivery of a construction project. Research studies conducted so far have been unsuccessful in delivery of an effective methodology that helps in analysing and managing the client risk factors at the early design stages in a construction project. To that context, the study aims to provide a new methodology for a client risk management model (CRMM). The study includes the development of a framework by integrating the findings from the literature review and a construction industry survey. A client risk analysis system is developed by integrating the analytical hierarchy process and Monte Carlo simulation underpinned within @Risk program. A case study is used to demonstrate the methodology and found that it is capable of managing the risks with a suitable risk mitigation strategy and supports the proactive actions at the design stage of a construction project from the client aspect.

Implementation of sustainability practices in construction projects is highly dependent on the policies adopted by governmental authorities. Therefore, it is critical for decision makers in authority entities to understand, in measurable terms, the possible consequence of implementing different policies and hence select the combination of policies that leads to optimum positive results. The objective of this paper is to present a framework for assessing the impact of different sustainability policies using agent based modeling and life cycle analysis. Under the presented framework, while agent based modeling is proposed to simulate the diffusion of sustainability in a construction market, discrete event modeling is used to map the interaction of main stakeholders in order to model selection of sustainability credits on a project level. Life cycle analysis is introduced as an objective quantifiable tool to assess the saved environmental impact associated with application of project sustainability credits as a result of targeting certification levels in light of the adopted sustainability policies. The saved impact on the level of projects is expanded to represent the full market and therefore reach an approximate assessment of the saved impact due to applying different policies. The proposed framework is designed to the case of the state of Qatar and can be utilized for other markets provided necessary customization is considered.

With the amount increasing, the Building Information Modeling or Building Information Model (BIM) data exchange and sharing face a series of challenges including integration of disparate data models, fast information extraction and data consistency maintenance. Since the existing BIM data storing and transferring method based on neutral files or a centralized database cannot meet the above-mentioned requirements, a framework of distributed BIM service on a private cloud platform was proposed. By this BIM service, multi-stage participants store relevant data on their own servers, which are virtually integrated through a cloud computing (CC) platform to form a logically complete BIM. It supports participants to establish, manage and transfer consistent BIM data efficiently while ensuring data privacy. To achieve this BIM service, a BIM integration and service platform (BIMISP) based on Industry Foundation Classes (IFC) and CC was developed. Proved by experiments, the research achievements are useful for improving the efficiency and quality of information extraction and delivery, ensuring the safety and legality of data sharing during building lifecycle.

In 2007, following continued dissatisfaction with the lack of cost certainty on publicly funded projects, the Irish government introduced the Capital Works Management Framework (CWMF). This framework had stated strategic objectives of: (1) achieving greater cost certainty at contract award stage; (2) better value for money at all stages during project delivery; and,(3) more efficient end-user delivery. The framework, in particular, sought to rebalance risk so that there was an optimal transfer of risk to the contracting authority and the contractor through the implementation of fixed price contracts. Coinciding with the introduction of the CWMF, there was significant debate around the introduction of Building Information Modelling (BIM) internationally, in assisting with the delivery of greater efficiency and, cost certainty of Public Works Contacts (PWCs). In this paper, the authors' aim was to investigate how best to align the virtues of BIM methodologies with the stated aims of the CWMF. In particular, this paper will focus on the experiences of PWC teams working on two recent pilot projects where lean and BIM technologies were deployed.

The tremendous growth experienced in the UAE construction industry has been mirrored by the development and expansion of the project management discipline. The UAE has had the unique opportunity of employing the best as well as adopting international best practices. This paper identifies whether project management, as a discipline, helps deliver the key project objectives - in particular, those of time, cost and quality. It further investigates whether project managers are involved at strategic levels with the power and authority to effectively influence the direction and course of the project or were merely relegated to a monitoring and reporting role at an implementation level. A survey was undertaken to test the performance of projects in the UAE and the use of established project management tools and methodologies. Analysis was undertaken on the results to compare them against an international benchmark and assess any correlation between those projects performing poorly and projects with poor use of tools and methodologies, or a poor ranking of the critical success factors. Over 33% of projects failed to meet their stated objectives in respect of time, cost and quality and were considered poorly performing. Project managers were generally well qualified in their primary discipline and experienced in the construction industry, but were less experienced in the field of project management - many with no formal affiliation to professional institutions. Although project managers generally had good knowledge of tools and methodologies, a significant proportion had either no knowledge or saw no practical use for the established techniques.

As-built drawings represent the final constructed projects. They are the contract drawings revised during construction and, before handing over, including all changes. They provide owners and facility managers with a proper reflection of a facility by which the necessary information is used for operation and maintenance processes. They are successfully used in developed industries in the world. This paper is mainly aimed to investigate the significance of buildings' as-built drawings in Dubai through examining the factors that determine their value in terms of availability, accuracy, impact on cost, time and safety. This work will study the significance of mismatches between final drawings and the as-built projects in villas, multi-story and industrial buildings. Technical reports of more than 170 projects were studied in order to analyse and assess the mismatches found at the final inspection for the completion certificate process. The results show 53% of buildings studied had mismatches mainly in external elevations, internal design features and fixtures, specifications, and general works omissions. Improving as-built drawings can be achieved by handling such mismatches earlier in projects' brief and design.

Green building materials are composed of renewable, rather than non-renewable, resources. Green materials are environmentally responsible because the impacts of the product are considered over its life cycle. Depending upon project-specific goals, an assessment of green materials may involve an evaluation of one or more of the following criteria: resource efficiency, indoor air quality, energy efficiency, water conservation, and affordability. Product selection can begin after the establishment of project-specific environmental goals. The main objective of this research is to develop a framework that uses BIM to select optimum sustainable building materials in Saudi Arabia. To this end, a cost model will be developed to take into account initial costs, such as construction costs, and all life cycle costs including the operating costs and energy consumption of a building. The framework integrates the expanded features of BIM technology with an especially designed green building rating system for Saudi Arabia.

One of the challenges in sustainable development is to optimize the energy efficiency of buildings during their lifespan. Modern concretes offer both low embodied CO₂ with the use of different types of cements and recycled aggregates and reduced operational CO₂ with the intrinsic property called "thermal mass" that reduces the risk of overheating in the summer and provides passive heating in the winter. Thermal mass is currently evaluated with "admittance", which is the ability of the element to exchange heat with the environment and is based on specific heat capacity, thermal conductivity and density. The aim of this study is to evaluate the effect of thermal properties - namely, density, specific heat capacity and thermal conductivity - on thermal mass. The objective of the study is to carry out laboratory experiments by measuring such thermal properties of concrete mixes with various percentages of ground granulated blast furnace slag (GGBS), pulverized fuel ash (PFA), and silica fume (SF) and recycled coarse aggregates (RCA). The results obtained from these tests would contribute to the evaluation of how such thermal properties influence the thermal admittance and, hence, the thermal mass performance of sustainable concrete elements in a building system.

Construction site layouts need to be planned for safety and efficiency before the site operations can begin. However, current planning methods rely heavily on the experience of planners. Inexperienced planners can easily neglect objects or misestimate object size and location during planning. This research aims to develop a video-enabled dynamic site planner that enables planners to model on-site objects from images from closed-circuit television (CCTV) and help planners to simulate the site in real-time virtual construction. Two main methods are developed in this site planner. The first is the rapid image planar modeling method, which enables users to rapidly construct 3-D geometric models of the on-site objects from the video image. The second is the video-based virtual construction planning method, which provides a process for site layout planning in a simulated virtual construction environment. We have implemented this site planner by using a game engine. After an example case pertaining to layout planning, the results show that this system can help planners identify potential problems that will occur in the actual site layout process. The system can also serve as an information platform to reduce the gap between construction simulation and reality.

This paper presents an ongoing work on using Unmanned Aerial Vehicle (UAV) in construction scenarios. Augmented reality (AR), the technologies integrating the real images and virtual rendering scenes, will also be integrated to enhance the application of UAV. The high viewpoint and the combination of real and virtual scenes provide engineers augmented views to the construction site. They will increase the possibility of discovering the unfound problems. We have designed and prototyped a UAV with features important for the construction management: (1) stabilized image capturer, (2) site level image transmission and (3) telecommunication and viewing interface. The stabilized image capturer includes a 2-axis brushless motor gimbal which can continuously adjust the camera to aim in a specific direction. The image transmission was carried out by using radio frequency transmitters which specifically optimized by considering the size of the construction site. The interface includes a multi-rotor UAV that has reliable telemetry control, a display that can render the mixed scene between virtual and real views using AR technology, and a wireless local area network (WLAN) system that provides access to real time image stream for multiple devices. From preliminary tests, we found the system has the potential for discovering unnoticed detail problems in a real construction site, such as vehicle path planning conflicts and structure spatial dilemmas. In the near future, we plan to test the UAV-AR solution in three common construction scenarios: typical building site, bridge inspection, and urban planning.

The article discusses the education informatization. Particular attention is focused on the development and introduction of modern information and computer technology to ensure high academic results and research processes.

Human mobility is central to our understanding of design, planning and development of civil infrastructure, particularly in urban areas where large-scale mobility flow problems can critically depend on the interface between human mobility and infrastructure. Therefore, researchers have spent considerable effort to understand and predict human mobility patterns. Several recent studies have used geo-social networking platforms to examine human mobility, but the focus of these studies has been on small scale social networking media. In this study, we examined the possibility of using Twitter - a massive online social networking platform with over 400 million users - to collect human mobility data. We developed a process map to collect data from Twitter and designed two Python modules for its implementation. A case study was conducted and its results confirmed that Twitter can provide a larger quantity of useful human mobility data. In future research, we plan to analyze the data and validate that it can accurately capture mobility patterns. This will provide insight into whether Twitter is a viable resource to study city-scale human mobility. It can also potentially deepen our understanding about the interaction between urban dwellers and civil infrastructure.

A variety of traffic data, such as traffic counts and speed estimations, can be harvested from camera network systems installed along highways. This is possible through computer vision-based traffic monitoring processes that are mainly composed of vehicle detection and tracking, and field of view calibration. Several such processes have been proposed; however, they have not been fully validated on managing occlusion-based scenarios and generating reliable data over long periods of time and high volumes of traffic. This paper presents an effective, semi-automated method of detecting and tracking highway vehicles. The method integrates automated calibration of the field of view, detection and tracking. Trajectories, lanes, speeds and counts of tracked vehicles can be obtained from the videos using the proposed method. When a vehicle gets occluded by the other in adjacent lanes, the method identifies it based on the speed and acceleration, and terminates the tracking. When the vehicle reappears, it initiates a new tracking process. For validation, the framework is tested on videos recorded from CCTVs along the I-85 in GA, and evaluated on the accuracy of vehicle counting and speed. The tracked vehicles are counted when passing by pre-determined counting zones to avoid double counting. The speed results were compared with GPS data. The results indicate that the proposed system has a potential to minimize human intervention and provide reliable counting and speed data.

Tools for the estimation of energy performance improvement - achievable through energy efficiency and renewable energy interventions, with decision-making capabilities for policy implementation at the neighborhood level - are still lacking. In this paper, we present a proof-of-concept tool that integrates a decision support mechanism for enabling opinions and criteria of various decision makers to be taken into account during the implementation of energy efficiency interventions at the neighborhood level. The tool is based on integrating information from aerial and terrestrial imagery, digital maps and national databases and statistics providing housing data on a GIS platform. The testing of the tool with the involvement of local authorities and social housing providers demonstrated that the tool can support policy makers in making informed decisions with regard to the implementation of energy policies and initiatives and contribute to meeting CO₂ emission reduction targets.

In Japan, when government and local agencies order public works, contract officials are mandated to set a threshold price which is the upper limit of the bidding price for each project, in Japan. We have developed and maintained "a cost estimation system" which computes the threshold price. In this paper, we present a model analysis using the game theory on the basis of micro-economy. The model to examine is based on an auction theory, which was developed considering game theory as a basis. We employed "first-price sealed-bid auction". It turned out that it is effective to support bidding and contract procedures complete smoothly, to add the data and logic on which the production cost of a tender company.

This article is based on my PhD thesis about creating a free, cloud-based tool that allows us to greatly simplify the process of zoning and urban planning using a combination of satellite data, altitude data and existing information about building. I analyzed existing programs and found ways to improve productivity of humans working in this sphere and decrease skills and education required for such work. The article describes flaws in existing programs and methods I use to correct deficiencies. I also tested my program and methods for measurement errors and compared results with existing methods, and the error margin is less than 2%. The few people to whom I asked to test the beta version of my software were able to do tasks a few times faster than in any other software. Compared to manual methods (still widespread in Russia), testers were able to increase time required for tasks from days to minutes.

Construction workers' behavior is an important factor of productivity and safety on a job site. Worker behavior is not only determined by individual's inherent characteristics, but also largely shaped by contexts which include the social interactions within a project. As a result, construction workers' behavior on a job site is under the influence of the social norms and work culture of their workgroup. However, our current understanding of the social aspect of worker behavior is limited. To expand our understanding of workers' social behavior and its impact on project performance, researchers have begun using an agent-based modeling approach because it allows researchers to observe the complex group-level behavior emerging from individuals' interactions. One of the important issues in using agent-based models for organizational research is enhancing the credibility of model predictions. With this background in mind, the objective of this paper is to propose a methodology that can help enhance the credibility of an agent-based model for the study of workers' social behavior using survey data. Specifically, it is suggested in this paper that the perceptual/attitudinal/behavioral data from surveys and the corresponding data from simulations be transformed into categorical data, and then compared to each other to show a quantitative agreement of the model behavior with empirical data. The proposed methodology is illustrated by an example of construction workers' absenteeism research that we have conducted. With the results of this research, it is argued that demonstrating the correspondence of simulation data to survey data using a data categorization method is an effective means to enhance the credibility of an agent-based model.

The objective for pre-hospital Emergency Medical Service (EMS) is to reach to, pick up, and deliver patients efficiently. By increasing the operational efficiency, the survival rate of major trauma patients could potentially be improved. In this research, the authors applied Moving Average, Artificial Neural Network, Linear Regression, and Support Vector Machine for the forecast of pre-hospital emergency medical demand. The results from these approaches, as a reference, could be used for pre-allocation of ambulances. The training of the models as well as the validation is conducted with data collected from the New Taipei City EMS. In order to represent the performance of forecast, the authors introduced the Geographic Information System (GIS) to manage and visualize the spatial distribution of forecast demand and error. Moreover, the authors built a flexible model which organizes demand data with the user given size of area and size of time step. With the easy use of model and acceptable prediction performance, the research outcome has its potential to be applied to the current practice.

Selecting the best conflict and dispute resolution method is not easy and can be very problematic, especially when the decision involves multiple objectives or attributes. Conventionally, construction parties consider cost, time and the amount of control they have in selecting their dispute resolution method. However, one of the most important issues is the intended relationship quality and future retention status of working relationships. Based on the range of potential relationship contingencies, the conflicting parties can decide on their potential strategy, style and method of conflict management. In the current study, four attributes (cost, time, control and relationship quality) are used to develop a multi-objective Decision Support System (DSS). Multi Attribute Utility Theory (MAUT) methodology is employed, the utility of these four selected attributes are defined, and the mathematical model is driven in two stages - stage one for each party and, in the second stage, for the integrated utilities of all the parties. The presented model, although having some limitations, can form the bases of a DSS for better selection of conflict and dispute resolution process.

Most engineering designs involve evaluation of several performance criteria. Usually these criteria conflict with each other and identifying good compromise solutions is difficult. While multi-criteria optimization approaches, such as Pareto filtering, have been applied to this task, not much attention has been paid to the selection of a single best solution. A new algorithm for selecting the best compromise solution that closely corresponds to the human decision-making process is presented in this paper. This algorithm, called RR-PARETO3, iteratively eliminates worst solutions according to multiple criteria from a population of possible solutions. A facade design example is selected for illustration and to evaluate the performance of the algorithm. It is shown that the algorithm is capable of identifying good compromise solutions that achieve reasonable trade-offs among conflicting criteria.

A number of solutions to cope with the problem of reducing power consumption by automated climate control systems are discussed in the paper. Interrelationships between the individual parameters of indoor thermal stability and the automatic control of climate systems were studied. The expression for calculating transmission coefficient of the controller was derived. The effect of structural room characteristics on the total energy consumption by indoor climate control systems is established. Conclusions are illustrated by numeric calculations with use of the developed computer program and graphic examples.

Much recent work has been conducted towards reducing the energy consumption of mixed mode buildings through rule-based automation. This paper presents a novel rule generation methodology through the simultaneous use of historical sensor data and theoretical models. The theoretical rule generation methodology will be explained, encompassing the development of an energy model to the inclusion of rules within the building specific ontology. This will include the development of use-case scenarios, their refinement through a sensitivity analysis and the generation of rules through an artificial neural network embedded evolutionary optimisation algorithm. Following a review of relevant literature, the methodology will be contextualised within the architecture of the KnoholEM project and applied to the first demonstration object, a mixed use public building in the Netherlands. An example of a rule generated will then be presented and the system will be considered within the existing solution space before comments regarding future developments.

Buildings constitute a large portion of energy consumption in the United States. Accurate forecasting of building energy consumption is integral to the implementation of energy efficiency initiatives and intermittent renewable energy supplies. The availability of high-resolution energy consumption data has allowed researchers to utilize machine learning techniques that forego domain-specific knowledge (e.g., building construction materials, geometric properties) to forecast energy consumption. While there is a growing body of literature surrounding the use of machines learning to forecast building energy consumption, previous research has yet to explore the use of feature selection to determine the most important subset of variables and produce interpretable predictive models. In this paper, we explore the use of Lasso, a shrinkage and selection method for linear regression that estimates sparse coefficients, to select the most important feature subset of a residential energy forecasting model. We evaluate the selected subset on an empirical data set from a multi-family residential building in New York City and compare the results to previous forecasting models without feature selection. Results of this work has implications on the data acquisition and sensing systems required to yield accurate predictions of residential energy consumption.

Healthcare is one of the most complex and energy-intensive industries in the United States. Healthcare facilities consume 836 trillion BTUs, spending more than $8.8 billion, 1 to 3 percent of the operating cost, and 15 percent of their annual profits on energy each year. Retrofitting healthcare facilities, from a small renovation to building a new department, is considered an important approach to overcoming these challenges and provides an opportunity to implement energy conservation measures. This paper focuses on the energy consumption of three retrofit projects in three major hospitals and compares energy consumption before and after the retrofit. Based on the information collected from the Facility Departments, simulation models for the selected retrofit projects were developed and Energy Plus building energy simulation program was used to model the facilities. Monthly and annual energy simulation modeling results, before and after the retrofit, are compared and analyzed to identify key factors and opportunities for saving energy in existing healthcare facilities.

Unintended air leakage through a building envelope is a major source of energy loss for residential buildings. Air leakage through improperly installed recessed lighting fixtures (RLF) has been identified as one source of unintended air leakage. However, little quantitative study was found on the energy loss through improperly-installed RLF. In this paper, the authors conducted preliminary evaluation of the magnitude of such energy loss by numerical simulations using 3D transient CFD model. One case was studied using boundary conditions of four seasons, which were obtained from historical experimental data from Mississippi. The results of the simulations indicate RLF can be a very significant source of energy loss in both summer and winter conditions. The study suggests that systematic approach is needed to improve the RLF design and construction practice to reduce or remove the RLF's negative impact on energy loss of residential buildings.

There is great potential for novel decision support tools to aid in the provision of tailored advice for both domestic and non-domestic buildings. The method described in this paper will rely on a combination of data from BIM - monitoring technologies such as smart sensors and performance-based analysis, user behaviour, and expert knowledge - for the development of a decision support tool for maintenance, retrofit and operation. It will present the concepts and research work behind the development of a novel tool to automatically generate maintenance and retrofit advice at different levels of abstraction, taking into consideration the requirements of different stakeholders, building performance analysis (BPA), standards guidelines and regulations. Design4Energy (D4E) EU project engaged into the development of an optimised design methodology which uses a decision-making tool based on expertise from a combination of different subject fields feed into a statistical model. Analytic Hierarchy Process (AHP) is adopted for the development of the tool as it uses priority theory which decomposes any complex multi-dimensional decision-making problem into a system of hierarchies. This looks into the historic type of experiences while predicting the future building performance and takes into account the operation scenarios and maintenance activities. It logically incorporates data and expert's judgement in the model to identify criteria to enables decision making.

The construction industry has had a high record of structural failures and safety problems for decades. Some of these relate to the inadequacy or instability of temporary structures. In many cases, these structures are regarded as static structures without appropriate monitoring of temporal changes in their stability. Developments in information and communications technologies, notably the advent of Cyber-Physical Systems (CPS), are changing the way in which structures are monitored. While significant deployments are being made in the structural health monitoring of constructed facilities, such as bridges, dams and other civil infrastructure, inadequate attention has been paid to temporary structures. With the bidirectional coordination possible between physical artefacts and their virtual representations, CPS offer an approach that can facilitate the monitoring and active control of temporary structures in such a way as to prevent structural failures and safety hazards on the job site. This paper reviews the key features of CPS, examines current CPS applications in the built environment and analyzes the applicability, potential benefits and barriers for CPS application to temporary structures. It identifies the promising application areas, and discusses how CPS could be applied in these contexts and the potential benefits.

The aging of highway infrastructure is a serious problem worldwide. As important constituents of this infrastructure, bridges have usually been inspected by visual inspection techniques and hammer sounding methods. In addition to these existing methods, different non-destructive evaluation technologies are also being developed and are expected to be utilized for effective management of highway structures. This study focuses on exploring and enhancing the usability of infrared thermography as a viable non-destructive evaluation technology. In this research, an experimental study was conducted to determine the most thriving time window to collect data from an object by using an infrared camera. The same setup was utilized to obtain data from existing structures. The results have shown that the night time was a better option to gather data from an object. It was also observed that infrared thermography could detect subsurface anomalies.

Cross-hole Sonic Logging (CSL) is the standard method used in evaluating the integrity of deep foundations for bridges, such as drilled shafts, and is based on travelling ultrasonic waves between probes in parallel tubes. Several studies have used arrival time and wave speed, such as in cross-hole tomography, to detect construction defects in drilled shaft foundations. A processing method for three-component wide-band CSL data is presented—named Frequency Tomography Analysis (FTA). It uses changes in color of the frequency amplitude of the received signal in the location of defects. The method transfers time-domain data to frequency-domain data of the signals propagated between the tubes using Fast Fourier Transform (FFT). The method is performed after a CSL test has determined the high probability of an anomaly in a given area. The procedure improves the location accuracy and further characterizes the features of the defect. The new technique is validated experimentally using two drilled shaft samples constructed with foam pieces inserted throughout the length of the shaft inside the rebar cage before concrete placement, to replicate construction defects. FTA is then utilized after the CSL tests to detect the location of the defects. The technique proves to have a very high resolution and can determine the exact location of any void or defect inside the rebar cage of a drilled shaft. This provides a significant improvement to current techniques used in quality control during construction of bridges.

Identification of important nodes/links is critical for understanding the resiliency of transportation networks in response to disruptions. Envisioning an intelligent transportation system requires effective monitoring of different components of a transportation network, such as nodes and links. For example, identification of critical nodes/links for placing different monitoring devices (e.g., cameras) is an important task of an intelligent transportation system. This paper is focused on identifying important nodes of a given transportation network based on a novel approach that minimizes the largest eigen value of an adjacency matrix of a transportation network. We tested the proposed approach on the Guam road network. Our results suggested that if capacities of 15% of the critical nodes are reduced by 50%, the connectivity of the entire network drops by 50%, which is significant performance degradation. The proposed approach is more effective than existing popular metrics (e.g., betweenness) in identifying a subset of critical nodes/links.

It is vitally important to evaluate costs, benefits and risks associated with adopting a new method or technology prior to field implementation. The present research proposes a framework for estimating potential cost savings by implementing new method or technology in the field in terms of: (1) productivity-dependent crew cost; (2) time-dependent indirect cost; and (3) time-independent indirect cost in the current practice that can be removed. In regards to system reliability, the proposed framework guides the identification of possible breakdown event categories and the evaluation of probabilities and consequences for each category of event. A case study is presented in the context of developing an innovative TBM guidance automation system in tunnel construction. Potential cost saving resulting from implementing the new automation system for a 1,000-meter-long drainage tunnel project in Edmonton, Alberta is estimated to be $346k, which far outweighs the additional cost associated with system reliability (about $ 34k) by about ten-fold.

This paper presents research on the mechanism of overturning failure on box girder under overload and partial load for the single-column pier bridges. It includes: (1) the definition of two key states before the box girder overturns (i.e., the disengaging state leading to the unbalanced load bearing and the ultimate state of overturning stability; (2) the depiction of three stages along overturning (stable stage, transitional stage, and overturning stage); (3) the development of an ABAQUS finite element model considering contact nonlinear and geometry nonlinear for analyzing Chunhui bridge collapse; and (4) the undertaking on identifying the relationships between overturning ultimate load and elastic modulus of box girder, load position, bridge length and friction coefficient of bearing and box girder. The results indicate that the overturning load calculated by finite element simulation conforms to the measurements collected at the collapse site of Chunhui bridge, reflecting the validity of the proposed study. The ultimate state of the overturning stability can be used to judge whether the bridge is overturning. It is more accurate than using the disengaging state of one side end bearing to judge, and the overturning ultimate load is 1.5-2 times than the rotating ultimate load.

Cracking is one of the most important features for identifying the current condition states of concrete structures. Structural engineers can analyze the cracking patterns and its extension over a period of time to make proper decisions on structural repair and/or rehabilitation. In this research, a crack detection system called "KUMONOS" - which is a total station equipped with a built-in crack scale - is described. The system generates a crack map with higher accuracy without reaching the structure within an arm's length, providing safer working environment to the inspector compared to the traditional close-up visual inspection method. Furthermore, the data obtained by KUMONOS can be integrated into the data from a 3D laser scanner or photogrammetry. The crack widths determined by the built-in crack scale varies depending on his/her experience and prejudice, causing certain amount of dispersion in the determination of crack widths. In order to minimize this dispersion, a methodology was developed to calibrate the human eye by providing a short training course. This paper describes the theory of crack measurement using the KUMONOS system, calibration training program, and some examples of the combined usage of KUMONOS with photogrammetry and a 3D laser scanner.

Civil infrastructures should be safe and kept in good condition, because they are important roles in economy and emergency services. If large-scale damage occurs to infrastructures in urban areas and they cannot be used, many aspects of life will be affected. Thus, it is important to protect infrastructures from large-scale damage in order to maintain services for the public. For local governments, it is necessary to act on disasters quickly. Disaster information should be collected and shared quickly for acting rescue and rehabilitation smoothly and effectively. However, in Japan, there are several problems for sharing the information in stakeholders. In this paper, a disaster information sharing system was proposed. The paper discusses the problems for submitting and sharing in disasters of earthquake, cataracts, flood, landslide, and so on. The prototype system was designed and developed using Web GIS. The system used was GeoServer and OpenLayers as open source Web GIS, and PostGIS and PostgreSQL as DBMS. The collection function was worked out by posting e-mail of disaster abstracts and photographs in site from local government staff and private engineers. The system put the point on digital map automatically analyzing e-mail. Local governments share the disaster information using Web GIS. The prototype was used for windstorm and flood disaster response exercise in local government for testing the usability and application in June 2013. The results showed the ability of the system for sharing disaster information. However, they showed the problems of usability and everyday use.

Embankment dams, like most other civil infrastructure systems, are exposed to harsh and largely unpredictable environments. However, unlike bridges, buildings and other structures, their design specifications and as-is properties are not generally known in the same level of detail due to, among other things, their age and the difficulties associated with assessing their internal structure. Hence, making sense of measurements collected from instruments used to monitor their behavior requires sound engineering judgment and analysis, as well as robust statistical analysis techniques to prevent misinterpretation. In the United States (US), the current practice of analyzing the structural integrity of embankment dams relies primarily on manual a posteriori analysis of instrument data by engineers, leaving much room for improvement through the application of automated data analysis techniques. In our previous work, we presented the effectiveness of applying statistical anomaly detection techniques - such as Principal Component Analysis and Robust Regression Analysis - when analyzing piezometer data collected from embankment dams. In this paper, we present how we could improve our work by testing with simulated anomalies that are indicative of internal erosion problems. In order to closely replicate more realistic anomalous scenarios, a physics-based model of an embankment dam was developed. By varying a hydraulic conductivity of a soil material in the model, corresponding detection accuracies and sensitivities of the statistical anomaly detection algorithm were evaluated. When we applied our proposed anomaly detection on more realistically simulated anomalous data using the numerical model, the detection accuracy came out to be 98.5%.

Life-cycle cost analysis (LCCA) is a necessary component in bridge management systems for assessing investment decisions and identifying the most cost-effective improvement alternatives. The LCCA helps to identify the lowest cost alternative that accomplishes project objectives by providing critical information for the overall decision-making process. The main objective of this paper is to present LCCA performed for different deck overlay alternatives using the recently developed deterioration models and latest cost data for Nebraska bridges. Deterministic and probabilistic LCCA using RealCost software for deck overlay decisions are presented. Silica fume overlay, epoxy polymer overlay, and polyester overlay are compared against bare deck with respect to the net present value.

The predominant method for infrastructure evaluation is visual inspection. The large number and scale of inspections often make it difficult to catalog the location, size, and severity of the identified damage. Several nondestructive methods can be used to detect cracks, such as acoustic emission and ultrasound, but they require the installation of many sensors, typically involve measurements in a predetermined area, and often require post-processing. Though image-based crack detection is limited to inspecting surface cracks, it has advantages including speed, repeatability, and large area coverage. Furthermore, the use of image stitching can provide a comprehensive assessment of the health of the entire structure. This method could also be applied using an unmanned aerial vehicle (UAV). This paper discusses major challenges in automated crack detection and implementation on UAVs.

Rapid detection of damaged buildings after natural disasters, such as earthquakes and hurricanes, is an urgent need for first response, rescue and recovery planning. In this context, post-event aerial images which could be collected right after disasters are valuable sources for damage detection. However, manual analysis process of the acquired imagery could be both time-consuming and costly. To address this issue, a series of classification models for post-hurricane automated detection of damaged buildings is presented in this paper. First, five feature sets were generated through feature extraction and transformation. Then, several classifiers were trained using two groups of classification methods: (1) the Minimum-distance and (2) the Support Vector Machine (SVM) methods. The effectiveness of these classifiers was evaluated in terms of classification accuracies and testing time. The results demonstrated the combination of feature sets and classification methods can provide the best performance. Furthermore, optimal classifiers were selected for future automated real-time damaged building detection. The observed performances of these optimal classifiers indicate promising application for a wide variety of image-based classification tasks.

In Japan, about 160 thousand road bridges are 15m or longer. These bridges are getting older year by year. The budget for maintaining them will be a big problem in the near future because the amount of budget for these infrastructure facilities has been reduced year by year in Japan. This paper studies the problem above and suggests two solutions. First, one is to review the theory of bridge life span. The general life span of a bridge seems to be 50 years in Japan; but, I think it is doubtful. I reviewed the original data and I found the life span of bridges must be longer. Second, one is to introduce new ways for local governments to maintain the bridges with smaller budgets by using new social systems and information technology. A new system in which a private cell phone will be used needs to meet conditions for residents, local government and requires the support for the local government.

A methodology is proposed for the seismic assessment of the reliability of urban water distribution networks (UWDN). The method is based on general seismic assessment standards, as per the American Lifelines Alliance (ALA) guidelines, and on localized historical records of critical risk-of-failure metrics. The proposed methodology is applicable to UWDN under either normal or abnormal operating conditions, and the assessment of reliability considers not only the vulnerabilities of the network components against seismic loading, but also the topology of a UWDN and data of past non-seismic performance. This past performance, obtained using records of pipe burst incidents, is utilized with network-specific `survival curves' in fine-tuning the generalized fragility curves suggested by the ALA. The resulting vulnerability analysis is used in devising `repair-or-replace' strategies for the studied lifelines.

Significant efforts are being made in the improvement of building automation and control systems in order to optimize the performance of buildings (e.g. reduction of energy consumption). As sensor networks in buildings increase, the complexity of managing them also increases. For instance, the generation and maintenance of meta-data about sensors, such as their location within a building, currently requires significant manual labor. The research described in this paper explores the relationship between different HVAC system sensor measurements and physical characteristics of spaces, and its potential application in streamlining the identification of sensor locations within a facility. The energy contained in the conditioned air delivered to each room is presented as a characteristic feature in order to understand the differences between rooms. Being able to understand the relationships between different measurement types and building characteristics is fundamental in achieving an automatic mapping of sensors in buildings, and this paper describes initial observations and results towards this goal.

Facility managers today inevitably deal with various tasks from daily operations. With the advances in facility technologies, the amount of data available is increasingly larger and more complex, especially for campus and healthcare facilities. A significant challenge is how to improve efficiency, productivity and profitability with limited resources, budget pressures and tight schedules, while still meeting the expectations of building occupants. To address such a challenge, this paper proposes an advanced artificial intelligence (AI) framework that utilizes agent modeling to facilitate system-wide decision-making for facility management. The framework is developed to help facility managers analyze and prioritize tasks according to factors such as degree of emergency, budget, and occupant satisfaction level, etc. Unlike previous construction industry agent models, this framework takes into consideration both the preferences and feedback of building occupants in the decision-making process for facility management. This paper realizes this framework through Any logic based on a real case study and proposes a unique algorithm. The AI model will combine opinions from facility managers and occupants to automatically generate an optimal task schedule. The simulation in a residential building demonstrates that the framework is feasible for dealing with real-world operations.

For infrastructure energy efficiency to reach its full potential, new and improved ways for occupants to engage with their energy use are needed. Despite the recent advancements in eco-feedback systems, strategies to increase motivation and user engagement in these systems remain primitive for a number of reasons. Improving the efficiency of user-driven energy conservation actions requires improvements in the delivery of energy consumption feedback, and methods that trigger occupant engagement with infrastructure data within eco-feedback systems. One approach to achieve increased engagement is through integrating feedback solutions with social networking platforms. This will enable feedback systems to address a larger population and to utilize persuasive engagement approaches such as: customized awareness, engagement motivations, and time/location-sensitive alerts. In this paper, we explore potential interactions between the occupants, infrastructure, and eco-feedback systems to examine the relevance of exploiting social media to increase user engagement in energy conservation actions. We examine the applicability and effectiveness of four eco-feedback systems from an occupant engagement perspective and identify gaps in these interactive systems. Finally, we propose a dynamic and interactive approach to feedback to enhance infrastructure energy efficiency.

Currently it is a critical situation when every year, due to aggressive external factors, thousands of listed buildings are under threat of destruction around the world. In many ways, the state of affairs is due to the lack of effective integrated management of listed buildings. Lack of an integrated tool for the operating of different data, which determines the structural integrity of listed buildings and condition of environment, has led to the fact that most of the regional and municipal authorities are not able to handle the diversity of information. To address these problems the specialist of Department of City Planning and Community Development of Rostov State University of Civil Engineering developed the methodology and information-analytical support system of listed buildings' preservation. Information technologies in management of listed buildings can help municipalities with a limited budget to get the most out of existing services as these are the technologies that help different departments to work more closely with each other.

This paper will introduce the actual development achievements and the key technical problems solved during the developing process of the "Digital Line Selection System of Urban Rail Transit (URT)". Chinese urbanization leads to increases in urban population and transportation demand. The URT construction and design was developed rapidly. However, existing URT design software cannot satisfy the using requirement which causes many problems. The Digital Line Selection System of URT was born to solve the existing problems of China Railway First Survey and Design Institute Group Ltd. The first part of this paper is about the actual achievements of development. The specific functions are mentioned as well, such as rapid construction with triangular grid DTM algorithm, the plane linear model, the interactive design of the "bell mouth" and custom of the grade line entity, etc. The second part will focus on the key technical problem-solving during the developing process. It began with DTM theory and method, and then made the plane general linear model. Next is management and free combination of line schemes and the mutual drive of geometry graph and the design data of the line. It also researched the station position design function of multi station type, the auxiliary line design method of unit and module combination. Finally, this paper will introduce the application of this system. The results show the development of this system is successful, and it will greatly improve the quality, efficiency and level of URT line designing, resulting in significant economic and social benefits.

Estimating and predicting the travel time on freeways with reasonable accuracy is essential for successful implementation of an intelligent transportation system. However, the related previous studies have some problems. The statistics-based methods have problems in accuracy, and some others are limited to predicting the travel time only during short time intervals. Another challenging matter is that the existing road sensors have some limitations in being directly utilized because data from road sensors have a lot of errors. In this study, we propose a new algorithm called multi-level k-Nearest Neighbor (k-NN), which is designed for predicting travel time with higher computational efficiency and prediction accuracy. The algorithm consists of three parts: classification, global matching, and local matching. As a part of the proposed algorithm, in order to overcome the problems of data errors, we provide a data fusion method that combines the traffic data from ILDs and DSRC. The results show that the proposed multi-level k-NN with the data fusion can effectively predict the future travel time within less than 5% error range, even in congested traffic situations.

Non-intrusive load monitoring (NILM) is a low-cost alternative to appliance level sub-metering, that leverages signal processing and machine learning techniques to estimate the power consumption of individual appliances from whole-home measurements. However, the difficulty associated with obtaining training data sets for the commonly used supervised NILM classification algorithms is a major obstacle in wide commercial adoption of the technology. The diversity of electrical load signatures (patterns of appliances' power draw) demands in-situ training (labeling of the signatures), which often needs to be performed by ordinary users through user-system interaction. To produce the example signatures required for training, continuous interaction with users might be required, which could reduce the success of the training process due to user fatigue. Pre-populating the training data set could help facilitate the process by reducing the number of user-system interactions needed for labeling. Taking into consideration all the issues described above, a study to test the feasibility of autonomous clustering of similar appliances' signatures based on hierarchical clustering was investigated. The information contained in the structure of the binary cluster tree was used for clustering without the need for a priori selection of the number of clusters. The assessment, carried out on data collected from a residential setting, showed promising results (with accuracy above 90%, calculated based on the ground truth labels) supporting the feasibility of the approach for unsupervised clustering.

In this paper, a framework is proposed for the investigation of base level components in the assessment of performance in construction projects. A multi-method simulation paradigm is proposed to provide a structure for bottom-up abstraction and modeling of construction projects based on micro-behaviors at the base level. The proposed framework and the model are used in a numerical example related to concrete pouring to evaluate the impacts of micro-behaviors at the base level on project performance. The findings of the case study highlight the importance of modeling the base level components and demonstrate the capability of the proposed framework in enhancing the assessment of performance in construction projects.

The U.S. National Highway Traffic Safety Administration has reported that the major cause of vehicle crashes in the United States has been driver inattention and distraction. Among various types of distraction, cell-phone dialing and text messaging have been shown to significantly degrade driving performance. Existing studies have mainly focused on driver distraction scenarios with one or a few vehicles, and have generally not looked at large-scale simulation of many vehicles. In contrast, currently available software for simulating traffic with many vehicles (e.g., CORSIM and VISSIM) has generally not considered the effects of driver distraction on driver/vehicle behavior. To overcome these limitations, we propose a computational modeling framework that integrates a cognitive model of distraction (i.e., Distract-R) and an agent-based traffic (micro-) simulation model (i.e., VISSIM). The framework aims to enable transportation modelers to easily set up virtual experiments and evaluate the impact of distracted drivers on large-scale networks. We validate the framework using two existing experimental data sets. Preliminary results indicate that the framework can account for statistically significant changes in speed fluctuation and headway distance in the presence of a significant number of distracted drivers.

In this paper, a basic Agent-based evacuation model is constructed firstly. On the basis of the integration of evacuation simulation model and Computational Fluid Dynamics (CFD) fire simulation model, a simulation model for occupant evacuation in fire environment, is proposed. Then, a powerful platform which can be adopted to incorporate BIM into 3D GIS is presented and the simulation scenario of occupant evacuation in fire environment can be implemented effectively on it. The research demonstrated that it is possible to transfer (high level of geometric and semantic) information acquired from IFC-based BIM models into the 3D GIS environment. The results also demonstrated that the 3DGIS-BIMs integration platform provide a sufficient multi-level and amount of geospatial and indoor information for the seamless data fusion and management tasks to support the fire response management processes considering both indoor and outdoor situations.

In this study, enhancement of productivity and efficiency of construction work throughout design, construction and maintenance is discussed. JACIC and Ministry of Land, Infrastructure, Transport and Tourism (MLIT) have been introducing and promotingConstruction Information Modeling (CIM) in the civil engineering field since 2012. Here, we focus on concurrent CIM model based on the information sharing/exchange system throughout the life cycle of structure and National fundamental infrastructure model to be used as common background information. To introduce activities of government on application of CIM/BIM concept in construction of public infrastructure, recently carried out model projects are also shown. Finally, idea of collaborative CIM design information systems is shown as a framework to support CIM/BIM activity and a possible role of JACIC in the context will be discussed. Furthermore, we show it about the development of the efficiency support system of the disaster-relief project that we cannot lack in and proof about the effectiveness of the topography model of CIM by the maintenance. We carried out the survey to explore and evaluate Photog-CAD based on photogrammetry technology on survey site support for local governments which is one of the solutions. It will enhance efficiency of survey work and three-dimensional terrain model for CIM and drawing recovery plan. Some of possible future developments presently discussed are also shown. This results have lead us to propose a concrete approach to be implemented in the method of promoting CIM.

LEED is a credit-based rating system that provides a third-party verification of green buildings worldwide. A building can obtain a Platinum, Gold, Silver or Certified grade based on the number of LEED credit points achieved. Selection of target credits is important and challenging for LEED managers due to limited budget, tight project schedule, and limited resources in many green building projects. Local climate factors like temperature can affect the selection of green building technologies and hence the LEED credits adopted. However, no research has been done to suggest LEED target credits based on climate factors. This paper aims to develop a decision support system based on climate factors for LEED credit selection using data mining techniques. The LEED for Existing Buildings version 2009 was focused in this study. Information of 912 certified green building projects and their surrounding climate circumstances was collected and studied. Classification models for 48 LEED credits that use credit achievement as the class and climate factors as the variables were then constructed and optimized using three data mining algorithms - Random Forests, AdaBoost Stumps and Support Vector Machine (SVM). The results were incorporated in a web-based decision support system. A case study was then conducted to illustrate and evaluate the system. The results showed that our decision support system has a high accuracy.

Like many green building rating systems, Leadership in Energy and Environmental Design (LEED) certifies green buildings as different grades according to the number of credit points the buildings have achieved. LEED project consultants often attempt to maximize the number of credit points to be achieved strategically with limited budgets and resources. For example, some green building technologies and features can be used to achieve multiple credits with little additional effort. Therefore, some applicants have studied the relationship and similarity in scope among the credits in green building rating systems, thereby finding ways to achieve multiple related credits. Some green building guides, such as the official LEED reference guide, also give suggestions on related credits. However, there has been a lack of study testing the strength of these suggestions. This paper aims to evaluate the strength of these suggested relationships by using data mining techniques. A database of certified green building projects was constructed based on the data from the USGBC website. The credits achieved by these projects were analyzed using association rule mining techniques. The strength of the suggested credit rules were identified according to the calculated outcomes. The results show that some suggested credit rules are related and commonly co-occur.

Sustainable housing retrofitting is an effort to convert a house to a low energy facility, to analyze the deconstruction techniques, and to evaluate the alternatives for installing reused/recycled materials. In order to make the decision of both designing and pursuing a green housing refurbishment approach, there is a need to perform a life cycle cost assessment to evaluate how each alternative influences the cost of construction, long-term costs (e.g., maintenance, utilities) and environmental impacts. This study presents a Monte Carlo simulation for estimating life cycle costs (LCC) of a case study house built in the 1960's. The study identifies the significance of proposed retrofit activities on the house's LCC. The results show that the cost of building may increase if we select a sustainable retrofit approach, but that the long-term costs would decrease. This paper also concludes that an optimum selection of retrofitting activities could minimize the life cycle cost of a project.

Over the past few decades, a growing number of qualitative and quantitative methods - such as echo-labels and urban metabolism - have been developed for environmental assessment of urban areas. Each of these methods has its advantages; however, none of them provides a solid framework which integrates life cycle thinking with multi-criteria and site-specific environmental assessment of an urban area. Recently, a few Life Cycle Assessment (LCA) practitioners have attempted to apply this robust methodology to urban areas to rectify the shortcomings of existing methods. However, methodological issues - such as definition of life cycle and functional unit of cities - as well as selection of appropriate system boundary hinder the application of LCA-based methods. This paper proposes using a well-known financial tool called accrual accounting along with life cycle impact assessment to provide a new framework for monitoring and evaluating environmental implications of urban areas. While keeping remarkable capabilities of LCA, the proposed method overcomes methodological problems and improves functionality of LCA-based assessment of urban environment.

Building life cycle assessment (LCA) is an important methodology associated with the sustainable construction. The LCA method enables the construction stakeholders to quantify and assess environmental impacts of construction activities, which ultimately helps them make more environmentally friendly decisions. Multiple LCA tools have been developed around the world in order to not only facilitate the application of the LCA method within the industry, but also to incentivize architects, engineers, and contractors to apply this method within their decision-making processes. Many of the existing LCA tools consider the life cycle of a building in five stages, namely - manufacturing, construction, operation, maintenance, and end-of-life. However, these tools lack when it comes to environmental impact analysis at building end-of-life cycle. This study aims to identify how much two well-known LCA tools (SimaPro and Athena IE) - which are currently in use in the industry today - support the building end-of-life cycle operations for making informed decisions. For this purpose, SimaPro and Athena IE are used to simulate the environmental impact assessment of a real world case study with different end-of-life scenarios. The results of this study highlight current deficiencies and benefits of these LCA tools along with a substantial need for a customized LCA-based tool which enables decision makers to make more environmentally friendly informed decisions at the building end-of-life cycle.

To promote economic growth, investments in infrastructure projects - such as roads, bridges, tunnels, airports, and urban mass transit systems - are indeed necessary. However, the growth in infrastructure investment is not without concerns. Transport sector accounts for a large amount of carbon emissions in recent years as the economy continues to expand. This paper presents a new framework of green growth assessment to be used for Thailand's highway infrastructure by combining economic aspects and environmental aspects of the project into a single index. The proposed method is intended to be served as a "green-growth" barometer of major highway projects across Thailand. To demonstrate how the proposed model can be applied in practice, Bangkok's motorway No. 9 is employed as a case study project presented in this paper. The results of this proposed method will be later used to evaluate the green-growth indices of major highways in Thailand. This study may help advance the knowledge and practices of sustainable highway infrastructure developments.

Low income housing is one of the most important housing projects that are directed to serve low-income people in Egypt. The greatest challenge that faces the Egyptian government is to decrease the cost of low income housing projects, taking into consideration the concepts of sustainability aspects. This paper presents a framework that integrates Building Information Modeling (BIM) with optimization in Low Income Housing Projects in an effort to assure sustainability. BIM is used to represent the geometrical information and the other properties of Low Income Housing building, such as building elements properties, material properties and its quantities, design alternatives and project location. On the other hand, Leadership in Energy and Environmental Design (LEED) rating system is used to evaluate the sustainability of buildings by awarding points for satisfying green building criteria such as regional material, recycled content, rapidly renewable materials. Genetic Algorithms (GA) Optimization is utilized in order to select the optimum building alternative that minimizes construction cost and duration, while achieving maximum LEED credit points. A numerical example is presented to demonstrate the practical feature of the proposed framework.

Improving the performance of existing buildings has provided a broad market for the green renovation of US building stock which is estimated at 76 billion square feet. Building Information Modeling (BIM) has had tremendous impact on the building industry by increasing productivity and document accuracy alone. The integrative nature of BIM technology renders it an ideal tool for implementing sustainable strategies into the renovation and/or retrofit of existing structures. By exploring the nature of the relationship of BIM and sustainability, as it applies to the built environment, the intent of this research is to determine what functions of BIM could be utilized to implement sustainable design principles into the retrofit and/or renovation of existing structures. The study sought to establish a sustainable framework for an evaluation and a set of "Best Practices" for the retrofit and renovation of projects seeking sustainable status. To provide a baseline in determining possible "best practices", a professional survey was conducted within the state of Florida, along with an analysis of a local existing structure. The survey focused on determining to what extent professionals utilize BIM to implement sustainable design principles in retrofitting/renovation and how BIM and sustainability impacted their practice. The case study investigated the process for conducting a total renovation with a goal of utilizing BIM in as many areas as possible to provide a sustainable outcome. To comply with current LEED rating systems, an evaluation was made to determine what level the alterations would achieve under the category of LEED 2009 NC. Although the LEED rating determination and level of sustainability depends entirely on the scope and nature of the renovation, results of this research show that BIM can be an effective tool in implementing sustainable design principles into the renovation and/or retrofit of existing buildings despite the scope of the renovation.

The evolution of sustainable assessment tools created a competition amongst well-known tools toward international use. However, practical evidence shows that regional and sociocultural variations have been a strong obstacle to the direct use of those sustainable assessment tools. Hence, this paper proposes to determine the applicable methodology supporting the adaptation of a sustainable building assessment method for any given region. The adaptation of the Saudi Environmental Assessment Method (SEAM) is taken in this paper as a subject of actual development. Because sustainable assessment tools involve multi-dimensional criteria, a mixed-methodology approach is used in conducting this study, given that the Delphi technique (DT) and analytical hierarchy process (AHP) have a proven record of reaching consensus by a panel of experts. Therefore, DT and AHP have been conducted, involving leading global experts in the domain of environmental and sustainable assessment schemes, as well as professionals and highly informed local experts from academia, government, and industry. The result shows that international sustainable assessment tools are not fully applicable to the Saudi built environment, as reflected in the development of a new building environmental and sustainability assessment scheme (SEAM).

The paper presents the evaluations and debates surrounding residential energy consumption in Saudi Arabia, a country distinguished by its fiercely hot weather and geographical position in a global area prominent for heightened energy consumption and carbon emissions. The cases chosen for the research comprise several residences situated in various climatic situations across Saudi Arabia. Specifically, the case study concerns multiple domestic buildings in the scorching, arid climate of Riyadh, multiple domestic buildings in the hot but humid weather of Jeddah City, and multiple domestic buildings in the hot, dry mountainous area of Al Baha City. The main objective of the evaluation is to identify the average energy consumption in the residential sector in Saudi Arabia, based on (a) monthly electricity bills for each residence, (b) occupant behaviour as determined by interviews for every chosen residence, and (c) analysis and discussion of energy consumption through modelling and simulation for every selected dwelling, using the IES-VE software tool. Energy consumption for the residential division is thus explored and debated, with an emphasis on architectural design, building materials used and occupants' conduct. Subject to established failures, several solutions were proposed with the objective of reducing energy consumption; they encompass shading techniques, renewable energy techniques, and efficient glazing. The proposed solutions were assessed by remodelling every residence using IES-VE, and the outcome was a decrease in energy utilisation, varying but reaching 37%, subject to local weather circumstances. The regional, financial and environmental benefits of the energy saving that would result from these measures being implemented for existing dwellings across Saudi Arabia were then presented.

Data envelopment analysis (DEA) is emerging as an important benchmarking tool for building energy performance with its unique capability of discriminating scale efficiency and management efficiency. Generally, the impacts of climate factors are desired to be neutralized to obtain a climate-adjusted energy parameter when using DEA for building energy performance benchmarking. Multiple linear regression is often adopted for this neutralization. While very useful, this approach rarely considers the multicollinearity trap referring to the statistical issue that the strong correlations among explanatory variables can lead to non-robust building energy regression models. This paper presents a simple alternative normalizing approach to avoid the multicollinearity deficiency in DEA benchmarking application through neutralizing energy input with degree day and floor area. First, the annual energy consumption of each building is normalized by its floor area and local degree day to acquire the degree day normalized energy use intensity (DEUI). Second, with each building as one decision-making unit, the DEA model is constructed with the number of occupants and the floor area as DEA outputs and DEUI as input. Finally, DEA is calculated to obtain overall efficiency, scale efficiency and management efficiency. The energy performance of 31 one-story residential buildings is benchmarked using the developed approach based on historical data. The case study reveals that the low energy performance of the targeted buildings is mainly due to the inefficiency of management factors, but further verification is desired.

The design of energy awareness solutions for the residential sector is a popular topic within research and innovation communities, with major industrial players being active in the field; the massive roll-out of smart energy meters in several countries is acting as a catalyst factor. However, the majority of existing solutions do not fully meet user requirements, thereby compromising their efficiency on the long term. A wider analysis is required, involving service designers, social sciences, contextual factors, and usability research. The aim of the ECOFAMILIES project presented in this article was to co-design with French families an innovative technological solution for getting a concrete understanding of their household energy use and consumption, and the choices that are available to improve it. The participatory design protocol went through three incremental workshops organized between March and June 2012 with 33 volunteers, complemented by a profile questionnaire, an online blog, the use of an eye tracking system and the making of a documentary film. The research contributed to discovering the real behaviors, attitudes and needs of these families when it comes to energy efficiency. A new prototype was developed alongside, featuring a fully customizable interface with widgets grouped by key topics of interest.

During the design phase of a building, there are often multiple options for selecting building materials and components that make up the building. This variety of options often results in multiple possible designs, each having different construction time, cost, and environmental impact. In order to determine optimal designs, optimization procedures, such as genetic algorithms, have been typically applied. However, current optimization procedures do not consider data uncertainties in productivity, environmental impact, and unit cost; thus, it is not known how data uncertainties may impact on the determination of optimal solutions. Simulation of Environmental Impacts of Construction, or SimulEICon, is a multi-objective analytical tool for observing relationships between time, cost and environmental impact during the early design stage of a building. In this paper, the extension of existing SimulEICon is discussed to include Monte Carlo simulation to account for data uncertainties and availability of data, and analyze their impact together with genetic algorithm-based, multi-objective optimization. Monte Carlo sampling is used to address the inherent uncertainty in the data. All data are behaviorally modeled using probability distributions based on various parameters and used to simulate the environmental impact, construction duration and cost of a building. The analytic tool is implemented by using MATLAB. The results are used to explain trade-off relationships between multi-objectives and to validate the impact of uncertainties. By observing results of different simulations it becomes evident that the effect of uncertainty is inherent to each solution set. This emphasizes how important the impact of uncertainty and availability of data is to a project.

This article discusses the use of cloud technology in the calculation of energy consumption of buildings; for example, the definition of the amount of energy consumed in the operation of the building, and the cost of its life cycle. In addition to the calculations, cloud services is useful for project teams. Members of the project team can simultaneously access, download, and edit the options granted to the project. With cloud-based solutions, they have virtually infinite computing power at their fingertips. Create, visualize, analyze, simulate, and iterate your designs faster-eliminating long wait time in studios or computer labs. Improve your course project outcomes by moving computation-intensive tasks to the cloud, enabling rapid visualization and simulation and optimized collaboration with access to intelligent, data-rich models. Solve your complex design challenges anywhere, anytime.

Today's design teams have to consider many different parameters and design options from an early stage, which can ultimately have a significant impact on the final performance of the building. Simulations can be used to help design teams understand the consequences of the decisions they take and assess potential variants. In the early stages of the design process, however, the information needed to conduct accurate simulations is often lacking. To address this issue, we developed a new method for Design Decision Support (DDS) that makes it possible to run simulations based on vague and incomplete input data using a method called surrogate modelling which implements parametric simulation data as a quick response performance model for the early design phases. This method is based on parametric simulation models that contain the required information. Designers can use these models to obtain instant feedback on their design and suggestions for further improvements. In our implementation, we have linked this system to a multi-touch environment that links physical volumetric models with the surrogate models, allowing designers to employ familiar approaches to design thinking. This prototype provides designers with direct access to energy performance simulations in the early design stages. This will be expanded in the future to provide further simulations.

As renewable generation capacity in the power grid increases, keeping the balance between the supply and demand becomes difficult. This threatens the grid's stability and security. Existing power reserve assets and regulation methodologies fail to provide the short-term responses required to keep the load and generation balanced as the amount of renewable generation increases. Hence, researchers proposed to increase the information exchange within the power network and to introduce real-time demand control to ensure robustness while accommodating the intermittent nature of these generation resources. Constituting a significant portion of the electrical demand of buildings, thermostatically controlled loads (TCLs) are well-suited to provide real-time demand control. In this paper, we shed light on challenges associated with engaging TCLs to the power grid using a centralized control strategy. We focus on the challenges associated with simulating a realistic TCL population using the models that are proposed in the literature. Specifically, we use data collected from residential refrigeration units operating in 214 different households to propose a strategy to select parameters when simulating a TCL population.

Improving occupants' comfort in affordable housing units has become a major priority in recent years to enhance the life-standards of their residents. Quantifying and maximizing occupants' comfort in affordable housing units is dependent on design and construction decisions that affect the occupants' thermal comfort, indoor air quality, and day lighting quality. This paper presents the development of a model to assist decision-makers in optimizing the configurations of single-family housing design and construction decisions to maximize occupants' comfort in affordable housing units while complying with annual energy cost constraints. The model incorporates genetic algorithms that are linked to an external energy simulation program, EnergyPlus. A case study is analyzed to illustrate the practical implementation of the model and evaluate its performance.