Computing in Civil Engineering (2005)

This paper examines opportunities and challenges that are associated with using sensors in civil engineering and proposes strategies for interpretation of sensor data. Opportunities include increased decision support and better modeling possibilities. Such opportunities have the potential to lead to safer, longer-lasting and innovative civil systems. Challenges include appropriate characterization of sensors, development of systematic methodologies for design of sensor systems, data interpretation and decision support. Meeting these challenges successfully requires consideration of the measurement context. Four contextual categories for sensor utilization are defined as follows: support during construction stages, warning of extreme events, system identification and experimental research. Regardless of the context, advances in model-based diagnosis have created the potential for reliable and robust computer support in many situations. A new methodology for sensor system design using entropy is presented and a model based approach for structural diagnosis is used to illustrate the potential of multi-model reasoning. Use of multiple models and consideration of contextual parameters are important for making the most of the opportunities that are available. The final conclusion of the paper is derived using an analogy of the paper title with the film "Sex, lies and videotape" It is necessary to go beyond being dazzled by the technology of sensors (sex) and the misuse of engineering models (lies) so that the interpretations we derive from combining the two (videotape) are as useful as possible.

Inelastic dynamic analysis of interacting soil and structure system up to failure poses very considerable challenges to a number of engineering sub-disciplines as well as information technology. Software platforms that offer reliable geotechnical material models do not have suitable structural models and vice versa. Provisions for uncertainty modeling in system characteristics and input motion, to quantify uncertainty in earthquake safety assessment, requires hundreds or even thousands of large, complex and computationally demanding analyses. The lack of a universally-capable framework for geotechnical and structural interacting systems is also a feature of experimental testing. No single laboratory has the range of equipment to test soil and structure and certainly no space to test even a medium length bridge or a medium height building. This paper presents a framework for the computational and hybrid computational-experimental investigation of complex structures, their foundations and underlying soil, when subject to earthquake strong ground motion. Emphasis is placed on the computational structure developed for multi-platform inelastic earthquake analysis of complex multi-physics systems. The framework comprises a central integrator and satellite components. The simplicity and transparency of the approach used lend themselves to fast implementation by research groups, and facilitate adding any number of analytical platforms. Reference application of the approach to seismic assessment of interaction problems is given.

Information Technologies (IT) are increasingly allowing for advances in monitoring and analysis of structural response. Sensor networks can provide real-time data streams, as a basis for system identification and decision-making. Fusion of video-derived information along with motion and strain sensors is already showing much promise. An integrated analysis framework encompasses data acquisition, database archiving, and model-free/model-based system identification/data mining techniques, towards the development of practical decision-making tools. Within this framework, data from experiments continues to provide much needed physical insight, as a basis for calibration of appropriate numerical models. In this regard, large-scale parallel computing and powerful visualization tools of soil-structure systems are a necessity.

The U.S. infrastructure is a trillion dollar investment, but we in the US have not been as aggressive as we should be in making better use of information and communication technology (ICT). ICT can be used to more efficiently and effectively construct infrastructure systems, monitor their performance, assist in the management of an entire set of assets, and assist in the operation of these systems. Advanced Infrastructure Systems (AIS) are defined here to refer to sensor data-driven and intelligent systems, components, devices and processes that improve the performance and/or reduce the life-cycle cost of a broad range of physical infrastructure systems. This paper presents a motivating vision for such advanced infrastructure systems, discusses some research within the Advanced Infrastructure Systems group at Carnegie Mellon that is currently being conducted towards this vision, and discusses responsibilities for delivering this vision.

This paper examines learning opportunities provided by the online engineering communities of practice. These communities are communities of professionals and others, who share knowledge and resources using the Internet as a communication and collaboration channel and a shared virtual community space. The discussion in the paper is based on a recent study of design features and functionality of existing online professional communities of practice, and on the authors' experience in teaching and development of the computer-based learning resources. One of the models for a virtual community of practice that provides great means for knowledge sharing and collaboration is the "Knowledge Portal" model. This model fulfills the basic online community of practice portal requirements including online learning resources that support learning opportunities for the members of the community. The authors discuss several learning scenarios enabled by the online Knowledge Portal and demonstrate how online resources could be used in the Civil Engineering materials curriculum. Within the conclusion, the authors recommend some design features and useful functionality of the online communities of practice that facilitate lifelong learning by the members of the community and enable wide-ranging learning opportunities for students that are entering the professional engineering field.

In the academic year 2004/2005 the first students entered a new postgraduate program called Construction Information Technology. The program is not only unique because of its content, which covers various interconnected areas of IT that are of most significance for the construction sector, but also because of its organization as well as the way of teaching. The program has been developed by seven European universities in the framework of the Socrates Erasmus project, and is delivered by teachers from all partner institutions. The purpose of such broad collaboration has more aspects. The students will not only get the best subjects the partner universities can offer in a specific area, but will also get the very important experience of other universities, countries and cultures, as well as of using IT in the learning and working process. Due to the spatial dispersion of students and teachers Internet technologies are being used to support distant learning. Great care has been taken to develop a flexible and effective learning environment to support various study activities. The paper describes the reasons for developing this new postgraduate program, it describes the development process, it explains the content of the program, and the learning environment. The paper concludes with the first experiences in delivering the courses of the new program.

Efficient and effective project control is the objective of all construction managers. Determining when and how to take action to control construction work has been the subject of much research. This research has been converted into theories that have gained acceptance and are widely taught in management courses. Despite this, the effectiveness of the techniques is almost impossible to prove. It is also very difficult to convey to students how their decisions will affect the success of their project. This paper describes a simulation model which is developed in the form of a management game as an alternative way for teaching construction planning and control. The simulation mimics the construction of a rock and clay dam where students need to plan, monitor progress, and control all contingencies which impede the timely progress of the construction. The paper also describes the application of the model and its efficacy as a learning tool by providing before and after studies to demonstrate learning. Finally the paper draws conclusions on both its effectiveness for control and on its use for teaching and learning.

Software is no longer developed and discussed only by computer science majors. Software development and engineering is a professional concentration area in architecture, engineering and construction (AEC) fields, among many others. Graduates of AEC related fields, who are motivated by problems which can be addressed better with computation or with better computation, often return to school to pursue graduate studies devoted to understanding computation of the professional problems they encounter. These students understand discipline specific issues in their fields well. However, in contrast to computer science majors, they lack techniques that can help them formulate solutions in software engineering terms. Asking such students to take classes from computer science curricula fosters interdisciplinary thinking; however, this practice fails to address the specialized computational needs of the AEC fields. An in depth understanding of how to use software development as a problem analysis approach can provide AEC students, both in the graduate and undergraduate levels, with problem classification techniques that they need. Here, we will describe our experience in introducing graduate AEC students to software requirement elicitation and development process techniques.

The paper presents structures of the learning domains of building informatics exemplified with experiences from building management civil engineering and open education in Industrial IT at Aalborg University. The courses cover areas such as; object oriented programming and relational database design, human computer interface, user environment design and usability engineering, computer supported collaborative working, knowledge management, virtual buildings, intelligent buildings, and building systems simulation. Experiences from many years involvement in ICT supported learning and development of ICT in construction courses are reported with particular emphasis on the Aalborg University Project Oriented Problem Based learning model, PPBL. Experiences from present and possible future use of virtual learning spaces and ICT tools to support teaching, learning, and (meta) information handling taking into account improvement of learning styles, course content and learning material is also reported.

An integration of CAD and Augmented Reality (AR) was previously implemented in a prototype system, Augmented Reality Computer-Aided-Drawing (AR CAD). The algorithm adopted for the real-time transfer of data between CAD and the AR viewer requires downloading the 3D solid model description at the client side via networking socket codes and supports only the AR rendering of piping system models. In order to get around the limitation of a required database, a polygonal data transfer scheme is proposed for any 3D solid models generated in a standard CAD modeling package. The approach decomposes the 3D solid model as a union of many single objects, which are in turn, approximated as groups of polygons. The vertex information of each polygon of a specific single object is extracted by a procedure which can operate on top of AutoCAD. Such data may be used by OpenGL functions in the AR viewer for real-time virtual model rendering.

Mechanical contractors acknowledge that the efficiency of current design review practices might be substantially improved by using 3D visualization techniques to amplify the effectiveness of the design review team. To reach this goal, the concept of a Mixed Reality-based collaborative virtual environment (MRCVE), has been formulated, which aims to support the collaborative design review process by enabling multiple parties to work on a routine task based on downscaled virtual models. One usable prototype based on the MRCVE concept is an MR-based face-to-face conferencing system, which could facilitate collaboration in face-to-face scenarios. This paper presents some results of an experiment implemented to demonstrate the capability of the system in realistic environments. The benefits of MR-based face-to-face conferencing were validated through comparison with prevalent paper-based 3D drawing review in the task of identifying design errors. The complete methodology, experimental design, experimental results and discussion are elaborated in the paper.

This paper describes the deployment of projection-based virtual reality (VR) systems and applications in support of architecture design studio and construction planning education and research in the Immersive Environments Laboratory (IEL) at the Pennsylvania State University. The lab has been developed as a test bed and proving ground to assess the value of immersive VR for day-to-day teaching and research in architecture, engineering, design arts and other disciplines. We describe the evolution of IEL systems through several locally developed designs as we approach the goal of providing affordable, scalable and relatively easy to use immersive display solutions. The work presented is within the context of teaching and research in architecture engineering and design. With a modicum of creativity, the open and modular methods used in developing the lab should be easily adaptable to new VR applications within many disciplines in science and engineering.

The characteristics of congested construction sites and simultaneous multi-contractor working environments require the general contractor or construction manager to coordinate and manage many trades to accomplish a project safely, on time, with the desired quality and within the project budget. To provide a conceptual framework for construction operations modeling, an innovative production flow concept in construction was proposed and elaborated in the early 1990's. In contrast to the traditional viewpoint of construction as activities, the production flow model conceptualizes construction as composed of flow processes. The benefits of using this perspective of production flow to manage construction include the provision of alternatives to a sequential model of project realization, improved construction quality and enhanced coordination among trade contractors. However, the understanding of this theory is limited by not only the abstractness of the concept itself, but also a lack of a visual representation of planning and evaluating techniques for implementing the production flow concepts. This paper presents a visual production flow planning methodology that integrates building elements, construction methods, and trade space occupation requirements for coordinating and sequencing construction trades on a project. The goal of the methodology is to provide a process for improving the visualization of the flow of trades on a project. The methodology achieves this goal by providing a process for planners to visualize trade flow space over time within a 4D CAD visualization environment. The model allows the user to plan and analyze the trade flow by identifying conflicts in trade flow space, trade flow direction, and trade flow continuity. A detailed case study was performed to validate the application of the methodology. This paper presents the methodology for planning, a discussion of the trade flow evaluation process, and an illustration of the application of the methodology on a case study project.

The notion of code checking automation in building design has been associated with different meanings and perspectives throughout the last twenty years of research, although the subject has remained always a challenge for AI experts mainly because of the very elaborate reasoning it demands. Basically, this activity puts together a certain kind of building description and a certain kind of code representation, seeking conclusions about the conformity of the former in relation to the latter. This paper discusses a new perspective on the subject, following the recent evolution in building modeling embodied by the IFC standard and presenting the certification of a building plan as a goal, as it results from the previously developed concept of a Normative Product Model.

Conceptual design decomposes in several subtasks and design actions at a detailed level which need to be performed in a right sequence. However, since sequencing knowledge, or design rationale, has not yet been incorporated into computational design tools for building structures, engineers cannot apply control knowledge from experienced practitioners to new situations in their practice. In this paper we present the theoretical background of a planning assistant that aims at satisfying such needs. The developed representation is based on expressive description logic and includes constructs for situations, subtasks, actions, and plans. The situation represents the developing structural concept and the current plan for sequencing actions and subtasks. Subtasks group the set of actions into suitable subsets to achieve a certain subtask and actions describes situation transitions of the developing concept. An interactive planning algorithm processes the representation.

Current CAD tools are not able to support the fundamental conceptual design phase, and none of them provides consistency analyses of sketches produced by architects. To give architects a greater support at the conceptual design phase, we develop a CAD tool for conceptual design and a knowledge specification tool allowing the definition of conceptually relevant knowledge. The knowledge is specific to one class of buildings and can be reused. Based on a dynamic knowledge model, different types of design rules formalize the knowledge in a graph-based realization. An expressive visual language provides a user-friendly, human readable representation. Finally, consistency analyses enable conceptual designs to be checked against this defined knowledge. In this paper we concentrate on the knowledge specification part of our project.

CAD applications have been developed for civil engineering with the intent to support the design process of engineers. So far, general acceptance of these solutions is limited to the support of technical documents. Requirements for extending the scope of CAD solutions in civil engineering are discussed and a solution is proposed for ensuring consistency of an engineering information model. Furthermore, virtually all solutions available today were originally designed as stand-alone solutions. A versioning approach for object models is proposed for supporting net-distributed applications in civil engineering. Finally, a system architecture is developed for engineering applications that is intended to support the workflow in civil engineering projects based upon a versioning concept for engineering object models. One important aspect of the system architecture proposed is a transition concept from current solutions to newly designed solutions. There exists a wealth of knowledge and data in engineering companies based upon commercially available CAD systems. Therefore, the authors believe it to be important to build upon this knowledge and information in order to show a path of growth from existing solutions to a next generation of CAD solutions in civil engineering.

Timely engineering feedback to the architect during the design process can result in improved building performance. Architectural sketches convey the architect's initial design intentions and explorations. As such, they become the first means for communicating with the structural engineer. The goal of this research project is therefore to provide the structural engineer with the mechanisms for devising feasible structural solutions from architectural sketches thus enabling early collaboration. This project is being carried out in collaboration with the LUCID group from the University of Liège, in Belgium. The project combines the strengths of two computer-based prototypes: EsQUIsE developed by the LUCID group for capturing and interpreting freehand architectural sketches, and StAr developed by the authors for assisting engineers during conceptual structural design. Such early collaboration assistance enables the architect to assess the structural consequences of his/her designs at sketching time without interfering with creative work, and it provides an opportunity for the engineer to get involved earlier on in the building design process and voice structural concerns in a timely manner.

This paper presents an object-oriented framework that gives attention to the features of simulation-based optimization problems such as hierarchical variables and the coupling with simulation programs. The framework consists of three basic modules: the variables module, the simulation module, and the optimizer module. The variables module defines variables and organizes them according to their relationships. The simulation module evaluates objective functions and functional constraints. The optimizer module implements optimization algorithms. The genetic algorithms implemented in the optimizer module can solve (1) unconstrained single objective optimization problems, (2) constrained single objective optimization problems, and (3) unconstrained multi-objective optimization problems. The application of this framework is demonstrated through a case study for green building design.

Computer-aided design and modeling software vendors have agreed that a Building Information Model (BM) is essential to reducing the cost and errors/omissions during the design and construction documentation process. However, this does not address the issue of interoperability throughout the facility life-cycle. The Architectural Engineering and Construction (AEC) industry has been making a substantial effort over the past several years to create a standard facility modeling format that better enables different software applications to interoperate. This emerging standard, known as the Industry Foundation Class (IFC), is being developed by the International Alliance for Interoperability (IAI) and can be found in recent releases of commercial AEC software. This effort has focused on design and construction applications and has just begun to touch the surface in modeling the needs of owners and operators. The Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) is currently developing a set of facility `architectural' programming tools, called Facility Composer (FC), to support the capture and tracking of facility criteria and requirements during planning charrettes. Planning Charrettes are key to capturing the stakeholder's (owners and operators) requirements in the early phases of project development. As the facility program, criteria and requirements are chosen during the charrette process, these tools populate the IFC object model. This object model can then be used for downstream analyses such as cost, sustainability, and force protection. As this model matures it can be used for the life-cycle of the facility.

The sudden disruption of utility services or contamination of a water supply endangers health, safety, and property, and significantly delays time-critical activities. Industry has developed vulnerability/risk assessment methods for individual utility systems; however, most of these methods are highly subjective and labor-intensive. Another concern is that most of the analysis methods only consider one utility service, such as electricity or water. This is an especially difficult problem for campus-type facilities where the public works department is responsible for providing all utility services to the customers. This paper presents a new interdisciplinary approach to utility system risk analysis. It involves using quantitative, engineering-based simulations of utility systems to support traditional assessment methods. The GIS-based simulation system used for this work allows individual utility systems to be overlaid and interdependencies to be defined.

Planning and construction of infrastructure projects for civilian and military applications usually involves a number of stakeholders, largely due to their geospatial extent and impact on the environment. These stakeholders bring different perspectives, goals, and criteria to the decision environment, complicating the task of arriving at a solution that is defensible and at least acceptable to most. Modeling and simulation technologies (simulations) are sometimes used as part of the collaboration process, both to provide quantitative data and to increase stakeholders' understanding of the implications of proposed solutions. These simulations are often expensive and time-consuming to produce, however, limiting their utility in the dynamic give-and-take of a collaborative process. This paper presents research to develop a framework and protocol that supports the integration of multiple simulation codes in a collaborative multi-criteria decision support environment. The approach posits that there is a common structure to multi-criteria problems, the decision matrix, which can serve as a basis for an abstract interface between simulation codes and decision support systems. This leads to a contract-based approach in which a wide variety of simulations can participate in a decision support process at low cost, by agreeing to provide criteria data and treat alternative data in a consistent way. The approach is demonstrated in a web-based collaborative environment using four plug-in simulations. The use of web-service based access to simulations is explored. Examples are provided of a land use change, deployment, and training range siting. The benefit of this approach is that it significantly decreases the time and cost of performing simulations, facilitating their use in collaborative decision support settings.

Geospatial modeling and simulation programs can be powerful tools for testing ideas, planning to avoid and mitigate disasters, and for evaluating infrastructure and other construction projects. The Fort Future suite of modeling and simulation tools is being developed such that it will minimize data requirements for integrated modeling. The system integrates several efficient models to simulate the infrastructure and activities in a community. It has a flexible architecture that is designed to support alternative models based on varying requirements. Fort Future is designed to allow model complexity to vary based on data availability. Many software simulations stand alone and require costly amounts of data to be collected for use with a single application. Fort Future enables the sharing of datasets between integrated models. The four models currently available in Fort Future, water, electric, activity and transportation, require substantially less data than other modeling software, and thus can be prepared more quickly and at lower cost. Because the models chosen are efficient, and they are integrated, their functionality is increased with data requirements minimized.

Process-orientation is an important approach for the support and the coordination of planning processes in civil engineering. Process-orientation relies on a comprehensive and consistent process model. The Petri Net theory provides some significant benefits for the application on process modeling, -analysis and -runtime control. This contribution outlines the basic idea of process-orientation and presents the goals of process modeling in civil engineering. Then a Petri Net-based process model for civil engineering processes is presented and the corresponding reference implementation ProMiSE (Process Modeling in Structural Engineering) is introduced. ProMiSE is a Java-based software tool for process modeling, -analysis and -control with network communication mechanisms based on the WebService technology.

Building design in civil engineering is characterized by the cooperation of experts in multiple disciplines. The close cooperation of engineers is the basis of a high product quality, short development periods and a minimum of investment costs. In contrast to most other design fields the development process in building design is characterized by the design of unique copies. For each building the engineers have to create a new fire protection model. As a result of huge fire disasters fire protection engineering is one of the central aspects for administrative authorities in the process of licensing the building design. Optimal conditions for the rescue of persons in case of fire only can be established, if the fire protection engineering conditions are created early in the planning process. The consistent realization of the fire protection model in all details has high demands on the communication and collaboration of the involved engineers and the corresponding building models. To preserve the related design models consistent to each other and compatible with the rules of fire protection engineering is a complex task. This leads to high demands on the semantic structure of communication, collaboration and building models. In addition, regulations and guidelines vary according to the building location, so the relevant rules must be integrated dynamically into the planning process. This paper covers the integration of engineers and design models into a cooperation network on the basis of mobile agents. Distributed models of architectural design, structural planning and fire protection engineering are supported. These can be accessed by mobile agents for information retrieval and for processing tasks. Agents which are enabled to check-up the distributed design models with the knowledge base of the fire protection regulations are provided to all planners. Thereby, the planners are supported to check-up their planning for accordance with the fire protection requirements. The fire-engineering-agent analyzes the design and detects inconsistencies by processing fire protection requirements and design model facts in a rule-based expert system. The possibility to check the planning information at an early state in the sense of compatibility to the fire protection regulations enables a comprehensive diagnosis of the design and leads to a reduction of planning errors.

Simulation is an approach which can applied to model construction operations and in particular at the construction planning stage. It can provide the necessary information to ensure that the resource allocation and construction methodology are appropriate to obtain the best possible project performance. In the particular case of road construction — characterised for the utilisation of heavy and expensive equipment and highly influenced by a number of risk factors — simulation can allow a thorough evaluation of all possible and feasible construction alternatives and provide analysis related to the compatibility between resources used in different activities. Also, very little simulation research work has been conducted in the area of road construction. In this context, the objective of this paper is to present a knowledge-based simulator that was developed in the course of this research that will be able to assist planners in the process of selection of resources, definition of the construction methodology, determination of the construction cost and time. The system is designated RoadSim and this paper describes briefly the respective features and capabilities, using an international contract as case study.

Precast concrete manufacturers are highly involved in the construction industry through the supply of make-to-order products. Their workload is a complex combination of different and unique designed products, which have various delivery dates. The production process from design to manufacturing is complicated and contains uncertainties due to many factors such as: multi-disciplinary design, progress on the construction site, and costly purpose-built moulds. An integrated, comprehensive planning system dubbed the `Artificial Intelligence Planner' (AIP) has been proposed to improve the efficiency of the production planning processes. AI (Artificial Intelligence) techniques are implemented in the AIP system to enhance data analyses and decision support for the production planning process. A case study for the trial implementation was conducted on a real make-to-order precast concrete manufacturer. The study concluded that the AIP system resulted in better production plans, compared to actual plans, with respect to customer lead-time, optimum factory's resource utilization, and in-house repository of production knowledge.

This paper is intended to demonstrate that contemporary computer simulations in civil engineering are different to conventional simulations of the past. In the majority of cases, conventional computer simulations have been based on numerical simulation models, particularly on finite element models solving ordinary and/or partial differential equations. Though such numerical simulations, besides theory and experiment, are rightly considered as one of the columns of knowledge gain, they do not fit the needs of the today's big challenges. Big challenges in civil engineering are characterized by a complex and intricate nature. More crucial, such tasks are founded on (i) a collaborative network of actors, (ii) a real world system or an abstract model of it, representing static, dynamic as well as functional (data flow) behavior patterns, and (iii) an environment. The environment acts upon the system or its model, but in turn also reacts to the behavior of the system or its model as well as to the events of the system's user, due to feedback mechanisms. To this end, the corresponding computer simulations require a multi-level and distributed approach where the individual levels themselves possess different scales in time and space. An aggravating factor is that the representation of each level is based upon different solution paradigms, not only numerical but also non-numerical ones, e.g. data-based, knowledge-based, event-driven and/or object-oriented paradigms. In the following, specific applications are given to elucidate and illustrate how this widespread category of simulation is becoming not only a new perspective in computational engineering but also the mandatory rationale for solving current, and future, sophisticated problems. Upon a general disquisition of the topic, exemplary research applications are scrutinized.

Microscopic simulation of traffic flow has spawned many different behavioral models, some of them commercially distributed, some developed at academic institutions for scientific purposes. These models are either kept secret (for commercial products) or substantially lacking in terms of usability and visualization. In this paper, we introduce the simulation environment BABSIM that allows for different driving behaviors to be integrated into one common simulation package. An overview of microscopic simulation is given, and several existing models and their implementations are being discussed. The fundamental structure of the BABSIM package, its user interface and the calibration of the model parameters are presented.

Structural monitoring is a distributed engineering task, frequently using visual methods or investigating local properties of a structure. However, with respect to tighter economic limits, it is becoming evident that in the next few years a paradigm shift is required from manually based to actively computer-controlled monitoring; appropriate automated Structural Health Monitoring Systems allow highly accurate identification of existing structural behaviors including possible uncertainties with regard to materials, loads as well as aging. Furthermore, the structural evolution with respect to deteriorations and damages can be precisely observed and the emergence of new degradations can be detected expeditiously. By installing a number of sensors at specified locations to monitor relevant parameters continually, it is possible to obtain an insight into the structure's state and the structural evolution, in real-time. This paper presents the development of an agent-based monitoring system for safety-relevant engineering structures that is currently being developed at the Institute for Computational Engineering (ICE): An artificial organization of several, cooperating software agents, which solve the distributed monitoring problem by using specific knowledge and by interacting both with other agents and with human experts involved in monitoring.

The present paper reflects the development of an innovative, agent-based software system for structural monitoring of dams which is capable of supporting the collaborative work of experts involved in monitoring. In contrast to conventional software systems, the agent-based approach is focusing on the distributed work flow of structural monitoring and considers structural monitoring as a result of collaborative work. For this, the complete work flow of dam monitoring is mapped onto a multi-agent system: the involved human experts are represented by personal agents, which assist the human experts in their daily work and allow a direct communication between the experts and the multi-agent system. In addition, regularly performed tasks are carried out by task-oriented agents. Supporting the collaborative work of multiple experts and the access to electronic measurement and control systems, the introduced concept provides a significant enhancement compared to existing monitoring applications. The present paper gives a short introduction to dam monitoring, then, outlines the conceptual design of the monitoring system and presents an insight into the current implementation. It is to be pointed out that the realization is still incomplete and a part of ongoing research.

An estimation of random fatigue processes in structural steel components requires the time-expensive execution of multiple numerical simulations. In the given case of wind loaded structures, the randomness is implied by the stochastic properties of the material and, additionally, the stochastic nature of the oncoming wind. To minimize the necessary computational runtime, a new software framework for parallel computations — based on agent technologies — has been implemented and tested. The parallelization has been accomplished by the usage of mobile software agents which can migrate from their original workstation to other computers.

Ground Penetrating Radar (GPR) is a nondestructive testing method used to test the integrity of roads, pavements, bridges and buildings. GPR uses high frequency electromagnetic waves at the Microwave or Radio Frequency range to investigate the subsurface. It is used to measure features such as pavement layer thickness, moisture content, horizontal cracks, and voids. The electromagnetic waves reflected from the interfaces in the subsurface are used to analyze the structure of the area under scan. This paper presents a case study of a section on the I-94 Highway at exist 30 in Benton Harbor, Michigan, USA. The objective was to investigate any defects, leaks, and air voids in the soil layers above the culvert, which is running under the highway and the exit ramps. These defects could cause damage to the lower layers of the highway and slowly deteriorate the condition of the highway. The results of this study indicated potential damage in some areas along the centerline of the culvert and in some locations that are a little farther from the culvert centerline. The results of the study will be presented in the paper.

The condition of the transportation network in the United States is Deteriorating and will require enormous efforts to significantly improve its state. Out of the 600 thousand bridges, almost 14% is structurally obsolete and another 14% is functionally obsolete. Concrete bridge condition assessment is a challenge to bridge inspectors because of the variety of problems that may exist. Therefore, the need for innovative inspection and maintenance programs is rising and new technologies are being applied to facilitate the detection of different defects that affect concrete bridges. An important component of the inspection and rehabilitation of concrete bridges is the ability to assess the condition of the bridge's deck. The advent of nondestructive evaluation techniques aided this task. Several nondestructive techniques have been successfully utilized to detect common defects in concrete bridge decks. This paper will study Ground Penetrating Radar (GPR) and Impact Echo (IE) abilities in the detection of the most common concrete bridge deck defects faced by inspectors using fabricated bridge decks with simulated defects. These simulated decks will be used to validate and compare the abilities of both methods in detecting the presence of cracks, delaminations, and voids.

Case-based reasoning (CBR), one of the artificial intelligence (AI) learning approaches, is drawing the attention of many researchers in Civil Engineering. However, due to vagueness and uncertainties in knowledge representation, retrieval, and inference of cases in CBR—especially when dealing with similarity assessment—it is difficult to find the cases in a case base which are exactly the same as the query case. Therefore, fuzzy theory has been incorporated into CBR, which promises more robust, flexible, and accurate models. In this research, fuzzy case-based reasoning (FCBR) has been used to develop a model for bridge management. This model can deal with multiple objectives, namely, predicting the future health condition of a bridge deck, and recommending the appropriate maintenance, rehabilitation and replacement (MR&R) actions. The FCBR model's learning capabilities have been validated using the cross-validation method. The code is implemented using the programming language C++, and all the cases used for both training and testing are extracted from the electronic bridge database of the Kansas Department of Transportation. In this paper, recommending MR&R actions, the second function of the developed bridge management model, is focused on.

This paper examines a system that could determine the thickness of the pavement in real time by laser scanning the surface of the subgrade prior to paving, and then scanning the surface after paving. By having this data, the pavement can be evaluated for conformance to project requirements for thickness. This paper also examines existing nondestructive methods of measuring pavement thickness including impact echo and high frequency ultrasound, and presents the advantages of each in relation to a scanning laser based system. Existing 3D imaging techniques are discussed such as shadow moiré, ground penetrating radar, stereo vision, and airborne radar. Laser scanning provides a thorough coverage of the pavement that will assure transportation authorities that the entire pavement surface meets thickness requirements. Other benefits from this technique involve being able to determine concrete yield quantities and possibly smoothness. This sensor will be able to provide real time depth measurements as a profile of the concrete will be generated. Volume of concrete in place will be easily determined using this approach. The system would fit on any paver that can provide position coordinates and may be retrofitted onto a paver by using relative position control.

A new method to detect cracks in concrete bridge images for bridge inspection automation is developed in this study. The algorithm divides the image into small blocks and identifies linear structures. A training set is generated by also segmenting them into blocks. Each block is treated as an individual entity in the training set. PCA algorithm is used to identify test image as an image with or without cracks. This local usage of PCA on small neighborhoods is to enhance the results as opposed to global search for the cracks. Real concrete bridge images with cracks of different sizes and shapes as well as non-cracked images are used. The algorithm development and implementation results are presented.

Three-dimensional modeling and visualization software is increasingly being used by building designers to represent structural frames and communicate design information upstream to their clients and downstream to suppliers/manufacturers. Although design processes and design management have been explored extensively per se, the upstream, heuristic decision-making stages of design in relation to 3D software appear to be under-researched. This is understandable because the human side of the process is complex and therefore less straightforward to map. Nevertheless, decisions made early in the project, such as the choice of structural frame, are critical to the project's overall success. Studies of current practice indicate that such decisions tend to be based on heuristic decision-making processes rooted in subjectivity and qualitative reasoning. This paper reports the development of an objective, transparent and systematic selection process that operates effectively within a 3D modeling environment. An innovative framework for simultaneously comparing the performance of a range of structural options against agreed criteria was developed, using the two measures, Importance (I) and Performance (P), which can be used to calculate a Performance Weighted Score (PWS). This framework is a means of assessing soft factors, alongside the conventional cost and time parameters now used in 4D modeling. It thus provides a useful example of a methodology for integrating soft decision making in an otherwise hard software environment.

Parametric approaches have impacted the work of specific industry sectors. However, AEC projects continue to struggle to integrate the work of many disciplines. The prevalent approach to integration has been to provide engineers with methods to construct a central model, simplifying the need to maintain integrity across multiple information representations. However, AEC projects have been slow to adopt this approach. The organizing metaphor of a central model, while conceptually understandable, may not adequately support the multidisciplinary, constructive, iterative and unique nature of AEC projects. This paper discusses an alternative formalization for a project's model, called Narratives, in which engineers from multiple disciplines formally and iteratively construct representations, called Perspectives, from information in other Perspectives and control the integration of this evolving, distributed, multi-disciplinary project model as the project progresses. Narratives enable engineers from multiple disciplines to engage in novel, automated, and integrated design and analyses. They are formal descriptions of a design process that can be reused in whole or in part on subsequent projects. We describe two Narratives addressing real AEC problems, one example as actually implemented, the other purely conceptual, discussing their potential to help AEC professionals to better design, communicate, integrate, and automate their design processes.

Entity-based modelling and Object-based modelling have been two distinct lines of products since the introduction of Computer-Aided Design (CAD) in the marketplace some twenty years ago. Although majority of practitioners have opted for entity-based modelling, the enhancement of object-based modelling has continued. In line with the increasing computer hardware and software capability, most CAD vendors have launched more powerful object-based CAD software in recent years. These software are now commonly known as Building Information Modeling (BIM), Virtual Building, Parametric Modeling or Model-Based Design. The move is considered to be revolutionary in the world of the construction CAD market, and would enable seamless downstream applications of the rich model information. Based on hand-on testing, this paper examines the provision of the data interfaces and the modelng objects in two BIM software. It is recommended that more user-friendly interfaces for embedding extra parameters into the modelling objects should be provided. BIM vendors should also support third-party development by enabling the application programming interfaces and data exchange standards such as IFC and XML.

Parametric three-dimensional modeling of buildings is assumed to offer numerous advantages over computer-aided drafting for structural engineers. Assessment of the extent and nature of the potential benefits is a difficult task because 3D modeling has yet to be adopted in practice and full-scale experimentation is both impractical and imprecise due to the unique nature of buildings and their individual design processes, which prevent comparison between control and experiment cases. Review and analysis of potential productivity measurement methods indicates that an approach based on benchmarking existing practice at the level of distinct engineering activities for complete projects, coupled with carefully designed experiments, can provide measures of the ratio of productivity gain and identify local process impacts and changes. The procedure and the rationale behind it are explained, and interim results are presented.

The rapid economic growth in china has generated unprecedented traffic demands on urban highways, which continues to worsen the environment by generating two environmentally negative by-products: traffic noises and air pollutions. If this trend of the worsening environment continues, not only will the public health and social environment be negatively affected, but also will the sustainability of the economic development be questioned, especially at a time when China is facing the challenge of organizing the 2008 Beijing Olympic game. In response to this challenge, Beijing Jiaotong University (BJTU), a national key higher educational institution, has established a comprehensive research agenda in the mobile emission controls. The university has been engaging in developing a full scale traffic environment laboratory (TEL), the first such lab in China, which is dedicated to developing traffic environment control strategies from transportation perspectives. The current experiment in TEL heavily replies on the use of an on-board emission monitoring equipment Montana OEM-2100. The nature of such equipment generates massive amount of on-road emission data that requires extensive computing capabilities to process as well as apply the data. This paper is intended to present the background of TEL as well as the research activities in this laboratory at BJTU, all of which involve extensive computing capabilites in six focus areas, which are especially important for the emission controls, but have not particularly been well studied for urban areas in China.

In environmental engineering numerical simulations are essential for analyses, forecasts and decisions. Usually, numerical simulations in hydrodynamics are based upon the finite element or the finite differences method. The quality of these numerical simulations depends strongly on the approximation accuracy of the topography. In addition, the efficiency of the mesh generation plays a decisive role for the applicability of a numerical simulation method. Nowadays, the generation of these meshes make use of high resolution topographic survey data, such as LiDAR (light detection and ranging), InSAR (interferometric synthetic aperture radar) or echo sounding bathymetry. These survey campaigns deliver a tremendous amount of data, needing to be analysed with regard to significant terrain features. The authors present a breakline identification tool for floodplains using a slope classifying approach. The detected breaklines are used for a hybrid meshing approach. This approach is based on a Delaunay refinement for the floodplains and a freeform surface approximation technique for the river bed. Accuracy and efficiency of this hybrid mesh generation approach are verified for an application in flood hazard assessment. The area under consideration is located in a typical part of the North German lowlands. The River Stoer is characterised as alluvial, partly straightened stream and is a tributary of the River Elbe.

Water distribution systems are susceptible to failures. It is common for a failure in the distribution system to cause a reduction in pressures nodal flows to consumers. In order to predict the reduction in the levels of service as a result of the reduced flows, it is important to relate pressure changes with nodal outflows during failure events. Conventional network analysis models are generally demand driven and do not allow the nodal outflow to be adjusted due to reduction in pressure. Modified network analysis is required where pressure dependent outflow functions are used. However many shortcomings associated with the pressure dependent functions have been reported in the literature. In this paper a modified network analysis program is presented where nodal outflows are developed as functions of pressure and secondary network characteristics. Outflow is estimated by means of an Artificial Neural Network (ANN) that has been trained with extensive data on pressure, flows and secondary network characteristics for a selection of secondary networks. A multi layer perceptron network has been used in predicting the pressure dependent nodal flows. The neural network is incorporated into a network analysis model and the network is solved using numerical differentiation. The developed model has been tested on several networks and found to be performing well. The changes in flows in secondary network as a result of the changes in the network conditions are predicted and compared with micro level models.

Imperviousness is a critical input parameter in stormwater modeling because it is directly proportional to runoff rates and volumes. Impervious surfaces are commonly obtained by means of aerial photographs, field surveys, and other analogue maps. But these methods are long and difficult. A more efficient alternative is to process satellite imagery. We propose the use of knowledge-based systems and GIS in delineating impervious surfaces from raw and normalized difference vegetation index (NDVI) images. We observe that with the refinement of rules in the knowledge base and with the incorporation of ancillary data, the computed overall imperviousness can approximate the value calculated from public records. Overall classification accuracy is also acceptable, the highest computed being 89.1%. We also compare our knowledge-based classifications with the maximum likelihood technique. We find that our results are generally more satisfactory. We conclude that classification with the addition of ancillary data using knowledge-based systems and GIS is better than classification based on spectral information alone.

The construction industry is typically characterised as being slow to change and to adopt new information technologies. Mobile technologies have been no exception; the primary reasons given for this hesitancy are the perceived lack of return on investment and an absence of industry-specific examples of successful adoption. A series of eleven case studies have been undertaken to facilitate the removal of these barriers. The case studies, detailed in this paper, were selected to demonstrate the use of mobile technologies by point-of-activity workers in construction, their influence on process efficiency, improved opportunities for data collection, and that rapid return on investment is usually achievable. The analysis identifies generic benefits of the applications and the lessons learnt provide clear guidance that should help ensure mobile technologies are appropriately deployed in construction. This paper concludes that the successful implementation of mobile technology typically produces a return on investment within one year of adoption, regardless of the initial set-up costs, and that the adoption of mobile technologies can make a significant contribution to the ongoing drive for process improvement. As such, they are a valuable tool to reduce some of the unnecessary costs currently inherent in construction projects.

Continuous commissioning focuses on optimizing the HVAC systems and the operation controls for existing building condition. However, currently the continuous commissioning processes overlook an important factor of user comfort. By not integrating the real indoor environment parameters the commissioning processes ignore the dynamics and the variations in the indoor environment which can affect the user productivity and hence the overall benefit. We built and deployed a pervasive sensor network using the CMU Critter Temperature Sensor to determine the effects of room usage on building conditions using real building performance data. Our results show that the building state is dynamic and the indoor environmental parameters vary significantly based on the usage of the room and layout. The results also underline the requirement for a pervasive, rather than sparse, sensor network for collecting building performance data. In our project, we plan to collect real time data from thousands of sensor nodes and do real time decision making for improving the building commissioning process. The challenges lie in the ability to process, store and manage the large amount of sensor data.

Product cost is a significant expenditure in a construction project where project participants have had to search for and dealt with a large amount of product information. With more product information, industry practitioners can make more informed project decisions. However, current approaches that support A/E/C information acquisition do not provide a comprehensive market scan. While the Internet provides an ever-growing resource for product information, none of the existing approaches is able to make use of this virtual market. Therefore, this research has developed a knowledge-assisted approach to tackle issues related to online searching to help retrieve A/E/C product information from the Internet. The developed approach utilizes (i) domain knowledge represented in the form of a thesaurus, and (ii) a knowledge-supported information retrieval approach adapted from the extended Boolean model. A prototype was implemented with five data sets for research validation. It was concluded from the testing results that domain knowledge can be helpful and the developed approach can effectively increase the number of distinct product manufacturers identified.

Typical public works departments around the world, at present, record complaints, work requests, and work orders related to their transportation infrastructure in a hard copy (paper) format. Further, the same format is used to assign work orders to staff. This is not only a tedious but also a time consuming process, often resulting in an inefficient and ineffective management of the resources. The goal, thus, is to look for avenues and explore the advancements in technology to improve the working process, and improve the efficiency and effectiveness of the infrastructure management process. This paper presents a framework for a computerized tool to manage and utilize resources for roadway infrastructure management. The computerized tool is developed using ESRI ArcPad Software, which is installed on portable or handheld computing devices. The development of the tool consists of three main processes: 1) data collection, 2) data storage, and 3) data distribution (or assignment). Data (complaints, work request, work orders) can be collected either over the Internet, by telephone, or in the field using a handheld or a tablet PC. Applications are to be developed to collect and store data in a comprehensive database for retrieval and processing at a later stage. Distribution (or assignment) of work orders mainly depends on the priority of the work order. Priority of the work order can be classified as emergency, urgent, routine and special. To make better use of the tool, spatial distribution of the work orders also need to be taken into account in the process of assignment.

The provision of real-time, context aware facility information to building operators, designers, and builders may dramatically decrease the cost-per-square foot to build and operate an enterprise's physical infrastructure. The Consolidated Facility Object Model (CFOM) extends Building Information Models (BIM's) by providing mission critical data on as-built conditions, facility carrying capacities, and facility production capabilities. Sensor technologies, such as Radio Frequency Identification (RFID), allow users to bring CFOM model data to the site on a need-to-know and want-to-know basis. This paper outlines the progress of research at the U.S. Army, Engineering Research and Development Center (ERDC), Champaign, IL during the period Oct 2003 to Apr 2004. Plans for the resolution of technology gaps and opportunities for implementation are presented.

Compaction grouting has become a popular method for site improvement around the world. However, in saturated soft clays, the treatment often induces higher excess pore water pressure and limits the efficiency of the improvement. To take advantage of the prefabricated vertical drain (PVD) and compaction grouting, a radial ground improvement technology (RGIT) was proposed for treatment of a site that was located on a thick saturated soft estuarine deposit. The treatment turns the compaction grouting into a radial accelerating consolidation process that increases improvement efficiency significantly. This paper describes a phase I study of RGIT by using finite element analysis to examine the field performance and develop design criteria for the construction. Based on the research findings, RGIT appears to be practical for soft clay improvement and demonstrated advantages over conventional compaction grouting. Confidence in what was achieved allowed RGIT to be used for the proposed site.

This paper presents a methodology for a combined flood and earthquake response simulation of levees. The methodology also incorporates the effect of inherent uncertainties in factors such as levee construction and design as well as flood and earthquake hazard on the response of the levee. The flood and earthquake response of levees is simulated using QUAKE/W and SLOPE/W programs. A levee model is defined using geometric parameters such as levee height, slopes, etc. which conform to the US Army Corps of Engineers levee design specifications. Several combinations of hazard levels can be specified using different flood levels and earthquake time histories. The factor of safety of the upstream and the downstream slope are used as damage indices. An attempt to simulate the response of all possible combinations would require thousands of computational runs. This unrealistic task is avoided by performing only a few model simulations, which are selected by a systematic procedure called the Design of Experiments (DOE) technique. Various model parameters that influence the levee response are first identified. The DOE technique is used to select only a few important combinations of these parameters. The Response Surface Methodology (RSM) is used to create metamodels of damage indices. In RSM, the damage indices are approximated by response surface regression equations in which the model parameters are used as predictor variables. The response of any combination of parameters can then be calculated using these regression equations. Also, probability distributions are assigned to model variables and the resultant probabilistic response is computed by performing a Monte Carlo Simulation (MCS) on the response surface regression equation. The entire analysis is integrated in a spatial framework where the response simulation can be viewed from ArcGIS interface. The methodology is used to analyze real inventory data for the levees near Memphis, which may experience simultaneous damage from the Mississippi river flood and New Madrid Zone earthquake.

Realistic finite element (FE) modelling of the tunnel construction process has been restricted by the computational effort needed to incorporate the three-dimensional (3D) aspects of the tunnelling operation. Two-dimensional (2D) plane strain models have therefore been widely adopted by practitioners and researchers in their studies of effects of tunnelling. However 2D modelling suffers the drawback whereby a volume loss must be assumed at the outset as the input for the FE model. This paper presents a feasible method of undertaking complex non-linear 3D numerical modelling of the tunnelling operation using Oasys LS-DYNA software, which utilises an explicit time-stepping method to undertake computationally efficient 3D modeling, without any assumptions regarding volume loss, but rather by modelling the excavation sequence and time-dependent gain in lining strength accurately. It is considered that 3D modelling techniques can be applied to different tunnelling methods in different ground conditions, and will provide an efficient means to estimate tunnelling induced settlement and the effects on nearby structures, without recourse to empirical estimates of volume loss.

When developing deep excavations in urban environments, a critical concern is the influence of construction-related ground movements on neighboring facilities and utilities. Ground movements may cause structures supported by the affected ground to deform and possibly be damaged. It is important to predict and control the extent and distribution of ground movements that result from constructing underground space. Currently, engineers can estimate ground movements using a combination of semi-empirical methods based in part on past performance data and the results from model simulation using numerical analysis. However these sophisticated analyses require accurate as-built construction staging data which most projects lack. The traditional approach of collecting field information is both labor-intensive and time-consuming. A system capable of gathering accurate as-built data in a timely manner would be highly beneficial for controlling and predicting ground movements in urban excavation sites. Significant developments in information technology are opening new ways to collect better as-built construction field data. A research team at the University of Illinois at Urbana-Champaign has been exploring the use of 3D laser scanning technology in urban excavation. Funded by National Science Foundation, this research field-tests the 3D laser scanning technology at urban sites in the Chicago area and explores better integration between engineering and construction field controls. This paper reports preliminary findings of the project, which include data from a five-month tracking of an urban construction site. It demonstrates the potential integration of 3D excavation data with finite analysis tools.

Building design is a multi-disciplinary process. The range of choices faced by the design team is vast and, given the time constraints that usually apply in the commercial world and the cognitive limitations of the human brain, the solutions reached by designers can be considered as no more than satisfying. Several research teams have been working on the development of techniques to assist building designers and help them locate good areas of the search space. The most promising techniques to date have used genetic algorithms as the search engine with parametric representations of the building and its properties. This approach has limited the designs that can be considered to buildings with regular column grids and rectangular floor plates. While regular column grids are commonplace, very few buildings are rectangular, especially in the Europe where construction sites are often based on ancient, irregular boundaries. This paper therefore describes a development of the above work using genetic programming rather than genetic algorithms as the search engine. This allows the use of a graph based form of representation, rather than parameters which coupled to additional features using a plane sweep algorithm allows the algorithm to produce building topologies for non-rectangular floor plates.

It is well known that for any sort of evolutionary search we must represent the problem solution in a suitable manner since the choice of representation has a large impact on the type and efficiency of the evolutionary search procedure applied. Usually in evolutionary design applications either bit strings or real number parameters are used to encode the problem. However, during the initial design phase a design may not be decomposable into real number parameters since the nature of the search space is not well understood and / or the designer wishes to maintain a highly flexible approach whilst establishing an initial configuration. The paper introduces the overall objectives of the project and discusses representation issues before presenting an object-based representation which tries to incorporate the ambiguity present during the initial design phase by working with design elements and objects as members of the chromosome. Ambiguity is particularly acute in this case as the overall project objective is the development of a user-centric evolutionary design system that includes aesthetic criteria evaluation.

This paper proposes a new approach to representing structural system inspired by various models of complex systems. Several types of generative representations of steel structural systems are provided and empirically investigated. These representations utilize various kinds of cellular automata to generate design concepts of steel structures in tall buildings. In the paper, a brief overview of the state-of-the-art in cellular automata and generative design is presented. Next, several types of generative representations of steel structural systems in tall buildings are described. The paper also reports the results of several design experiments. They have shown that generative representations produce novel structural shaping patterns which are qualitatively different than the patterns obtained using traditionally used parameterized representations. They also significantly improve the performance of evolutionary algorithms optimizing the structural systems. Finally, research conclusions are presented and most promising paths of future research are discussed.

This invited paper discusses research and development relating to computational intelligence (CI) technologies comprising powerful machine-based search and exploration systems that can generate, extract, process and visualise high-quality information from complex, poorly understood design domains. The integration and capture of user experiential knowledge within such systems in order to stimulate, support and increase understanding is of particular interest. The manner in which appropriate user interaction can overcome problems relating to poor design representation within systems utilising evolutionary computation (EC), machine-learning and software agent technologies is investigated. The objective is the realisation of user-centric intelligent systems that overcome initial lack of understanding and associated uncertainty; support an improving knowledge-base and stimulate innovation and creativity.

Bridges are vital links in infrastructure road networks and require frequent maintenance and repair to keep them functional throughout their service lives. However, with most existing bridges being old and the funds available for repair being limited, the prioritization of bridges for repair, the allocation of the limited funds, and the selection of appropriate repair methods become complex optimization decisions. This is still true even when considering only one bridge component (e.g., deck) within a large network of bridges. In this paper, an integrated bridge deck management system is formulated with detailed life cycle cost analysis. The system's implementation on a spreadsheet program is briefly highlighted. Five evolutionary algorithms namely; genetic algorithms, memetic algorithms, particle swarm, ant colony systems, and shuffled frog leaping are then introduced and applied to optimize maintenance and repair decisions for various problems with different numbers of bridges. Based on the results obtained, the benefits of both the model formulation and the use of evolutionary algorithms are discussed, and the most suitable algorithm is selected for the proposed bridge deck management system. This paper contributes not only to the development of advanced management systems that can be adapted to various infrastructure types, but also to the implementation of new techniques for large scale optimization.

Direct search methods offer potential for rapid exploration of a design space, enabling novel and optimized designs to be generated. We present the use of modified pattern search for optimizing the topological design of the bracing system for a free-form building of approximately 250m in height, carried out as part of a live building project, with the goal of generating alternative randomized patterns that meet structural performance. The methods developed successfully evolved efficient bracing configurations, in a procedure involving successive bracing element removal, with substantially less computational effort than a basic automation method. The diversity of solutions introduced by adding a stochastic element to the search procedure and stochastic variation of the initial design proved beneficial for the structural design team. The project successfully applies an established search method, tailored for this scenario, to a complex, large-scale design task and provides a valuable case-study in applying structural topology optimization on live building projects.

PGSL (Probabilistic Global Search Lausanne) is a direct search algorithm that is based on global sampling of the search space using a probability distribution function. PGSL has been applied to tasks such as design, diagnosis and control. In many situations, PGSL outperforms genetic algorithms and simulated annealing. This paper provides a summary of selected engineering applications of PGSL. Examples are timber shear wall design, model identification of structures, leak detection in water networks, control of tensegrity structures and optical measurements. The paper demonstrates the wide range of applicability of PGSL to engineering tasks.

The Multi-Objective Domain Knowledge Augmented Genetic Fuzzy System (MODA-GFS) is a GP based fuzzy system for the data-driven generation of fuzzy rule based systems. The algorithm incorporates domain specific knowledge that is used by human knowledge engineers in the manual fuzzy system design process. The combination of characteristics of two individuals is most interesting if both individuals complement each other. In terms of fuzzy systems this means a potential crossover partner (parent B) has a lower approximation error in an area of the input space, where parent A has a higher error. Within MODA-GFS a method for the determination of feasible crossover mates is implemented. In addition MODA-GFS includes a method for the goal-oriented selection of parent rules that are handed down to the offspring. Especially in the domain of knowledge representation the quality of a fuzzy system is not only determined by its approximation capability but also by its transparancy. In order to assure the automated generation of fuzzy systems that are both accurate and transparent multi-objective optimization methods are implemented. Tests carried out on test functions as well as on real world data sets have shown that the incorporation of domain knowledge significantly speeds up the evolution process. Besides these test results the integration and application of the new methods for automated generation of fuzzy models within a learning expert system environment are described in this paper. Finally an outlook on the current and future work is given, i.e. the transfer of the presented findings to the evolutionary optimization of large-scale structures.

Currently engineering design information is poorly presented. There is an urgent need for systems that allow proper visualisation of the information in an understandable manner which assists members of the multi-disciplinary team to comprehend the overall knowledge of the multi-disciplinary design issues. The need for such systems is particularly important at the conceptual stage of the design process where more important decisions about the future of the projects are being taken at a very short time span. The research presented in this paper has tried to take initial steps in this direction by developing an interactive visualisation system that assists designers by using various visualisation tools and techniques to develop a deeper understanding of the search and solution spaces and supports them in evaluating the merits of alternative design solutions within a multi disciplinary environment.

Average stopped delay for a given signalized intersection approach is the average time a vehicle waits at the traffic light and it constitutes a part of the measure of effectiveness of signalized intersections. The exploratory work done by two authors of this paper using images created by the animation feature of the CORSIM traffic simulation software indicated that such application can actually produce stopped delay estimates commensurate with the results of the ITE method. However, CORSIM simulation images do not have parallax problems and vehicle color and size and pavement color were practically the same for the entire evaluation field. The three methods (Gap, Gap-hybrid, Motion method) developed in this study are able to overcome to an acceptable level these problems associated with actual traffic flow images. They were tested with the two image data sets that were taken at two different locations with different camera angles. The performance of the three methods varies depending on the quality of image, camera angle, and calibrated parameter values used for each method. Nevertheless, in both cases they were able to produce average stopped delays similar to those estimated by the ITE manual method. At present the software that executes the three methods analyzes one approach lane at a time using digitized still images taken from analog video films; however, it can be expanded to analyze multiple approach lanes and digital images dynamically fed by digital traffic monitoring cameras. With this automated procedure the traffic engineer can estimate average stopped delays in his or her office, greatly saving time, money and manpower necessary for conducting field data collections.

The computer model MOBILE6.2 is widely used in the USA as a standard mobile emission estimation model. The developed prediction patterns and the associated parameters were mainly based on the prior laboratory tests. Although it is suggested to substitute the default fleet input data with the local data, difficulties still remain for this model to provide satisfied emission estimations. In order to understand the bias in using MOBILE6.2 in a particular area, the second-by-second on-road truck emission data were collected by using the newly developed Potable Emission Measurement System (PEMS). The large amount of testing data were processed and statistically analyzed via the MS EXCEL and a set of VB based programs. Data processing yields the temporal and spatial distributions of truck emissions as well as the relationships between emissions and the truck activity data. The aggregated on-road emission data were compared with the computer model MOBILE6.2 estimates. Results show that the tested data are mostly higher than MOBILE6.2 estimates. More testing and further quantification analyses are suggested.

This paper presents the application of a simulated annealing algorithm as an optimization method for finding a suitable combination of VISSIM parameter values. Four weaving sections are simulated in VISSIM platform using field data coming from Traffic Information Collecting System (TICS) in Shanghai. Numerous simulation tests indicate the main parameters affecting simulation precision are Desired Lane-Change Distance (DLCD), Witting Time Before Diffusion (WTBD), and Wiedemann99 car-following parameters CC0 (the average desired distance between stopped cars), CC1 (the headway time (in/s) that a driver wants to keep at a certain speed), CC2 (safety distance a driver allows before he intentionally moves closer to the car in front). The prepositional parameter combination of DLCD, WTBD, CC0, CC1 and CC2 is 300, 90, 1.5, 0.8 and 3.50 for peak time and 200, 45, 1.5, 1.0 and 5.0 for midday off-peak traffic.

Flexible pavement design is currently evolving from a qualitative design procedure, based on road test data, to a mechanistic-empirical design procedure. To support the upcoming standard of design, a data acquisition plan has been developed for a full-scale field test to be performed on a heavily instrumented flexible pavement with 13 test sections. The data will be utilized during a finite element analysis to generate design charts for flexible pavements reinforced with geosynthetics. The data acquisition plan developed during this study is designed to minimize the collection of unnecessary data and post-processing effort by using independent trigger mechanisms in each test section. Prior to full-scale construction, a pilot-scale study was employed to determine and verify the critical program acquisition parameters and test the trigger mechanism. Additionally, the data acquisition hardware and software code generated for this application were evaluated. The objective of this paper is to describe the results of the pilot-scale study, outline the overall data acquisition methodology, and highlight the key programming challenges.

This paper proposes an Anisotropic Mesoscopic Traffic Simulation (AMTS) model that is shown to exhibit distinct advantages in modelling traffic flow dynamics. The AMTS model explicitly represents individual vehicles, but assigns only macroscopic movement characteristics to them. This paradigm is of particular advantages when used in the simulation-based Dynamic Traffic Assignment (DTA) systems that have been under active developments in the last decade. This paper discusses basic traffic properties and the AMTS model, and demonstrates its capability through numerical analysis.

Transportation officials are faced every day with competing investment demands, and they must distribute limited resources in the presence of uncertainty or in the absence of complete and accurate information. Therefore, they must have access to valid, efficient, and robust asset management tools, which can support the optimization of maintenance interventions and support the policies at all decisional levels. Within this context, emerging technologies, such as artificial intelligence techniques, provide efficient alternatives to the traditional mathematical approaches. In this paper a hybrid approach for optimal management of road pavement maintenance for a pluri-annual planning period is proposed. The proposal of the procedure has been the optimal management of the rehabilitation interventions of pavement friction. In particular, a Sideway Force Coefficient prediction model has been created through an appropriate neural network to characterize the pavement conditions. Defined this model it was possible to solve the optimization problem. A genetic algorithm was used to tackle the combinatorial nature of the network-level maintenance programming. The procedure was applied to a motorway infrastructure belonging to the motorway network of Eastern Sicily (Italy).

Identification of high risk zones is important to develop and implement strategies to enhance pedestrian safety. While the analysis of motor vehicle related crashes has seen the use of Geographic Information Systems (GIS), pedestrian related safety analyses have not taken as much advantage of the capabilities afforded by GIS programs. The objectives of this research are to present a methodology to identify and rank high pedestrian crash zones, and to introduce a GIS based tool based on the methodology. Capabilities of the tool include the following: identify spatial concentration patterns, select high pedestrian crash zones, extract crash and demographic characteristics of the selected zones, compute crash rates, and rank the high crash zones. Data from crashes and incidents reported by law enforcement personnel and street network characteristics are used by the tool. The tool has user friendly interfaces for data input and customizes various repetitive tasks. While the application of the tool is illustrated using data from Carson City, Nevada, it is readily adaptable for analysis of data for any other location.

The continued improvement and application of Intelligent Transportation System (ITS) data collection technologies has generated higher requirements on the hardware and software capabilities to store, transmit and process the data. A cost-effective approach to enhancing such required capabilities is to use an ITS data compression technique. The purpose of an ITS data compression technique is to effectively compress and reconstruct the ITS data for being easily archived and transmitted. Nowadays, the signal-processing techniques have been widely used for the general data compression purposes. These techniques have a great application potential to the ITS data. This paper is intended to develop a new ITS data compression and reconstruction approach based on Wavelet Transform, Discrete Cosine Transform (DCT), Quantizing and Coding techniques in the signal-processing field, by designing the appropriate feature-distilling threshold and quantizer. The objective of the compression is to minimize the data redundancy, keep the maximum amount of useful information, limit the level of distortion and improve the data quality and application efficiency. To illustrate the effectiveness of the proposed model, the traffic flow data from the Beijing's Third Ring Expressway are used for the case study. By comparing the reconstructed data with the original raw ITS data, it is demonstrated that the application of the proposed technique has increased the compression rate by 61.92 percent in comparison with the widely used WinZip software. On the other hand, only 5.35 percent of the data has shown a larger-than-five-percent error between the reconstructed and the original raw data. Therefore, the proposed approach has achieved a much higher compression rate with very limited level of distortion. The application of the proposed technique would contribute to the reduction of the required storage space as well as the improvement of the transmission speed for the ITS data.

In this study, a highway product model was built based on the length data using functional representation of alignments. The Highway Sequence Editor (HSE) was developed as a system to be equipped with the model. It was shown that the model developed in this study was effective and that building systems that could increase design efficiency was possible. It was also shown that the design data built in HSE were described by XML, structured plainly and could be handled as uniform design data. A consistent system could be built by incorporating alignment design in highway space coordinates.

This study presents a substructure based parallel linear solution framework for the static analysis of linear structural engineering problems having multiple loading cases. The framework is composed of two separate programs designed to work on PC Clusters having the Windows operating system. The first program is responsible for creating the optimum substructures for the parallel solution and first partitions the structure in such a way that the number of substructures is equal to the number of processors. Then, the estimated condensation time imbalance of the initial substructures is adjusted by iteratively transferring nodes from the substructures with slower estimated condensation times to the substructures with faster estimated condensation times. Once the final substructures are created, the second program starts the solution. Each processor assembles its substructure's stiffness matrix and condenses it to the interface with other substructures. The interface problem is solved by a parallel variable band solver. After computing the interface unknowns, each processor calculates the internal displacements and element stresses or forces. Examples which illustrate the applicability and efficiency of this approach are also presented. In these examples, the number of processors was varied from one to twelve to demonstrate the performance of the overall solution framework.

In order to face up to the traffic congestion problem, many cable-stayed bridges are designed with a large ratio of width to span. This results in significant shear lag effect to cause nonuniform stress distribution along the flanges of the beam. This paper presents a study on the shear lag effect and dynamic properties of the Xiaoxihu Yellow River Bridge. A three-dimensional finite element model of the bridge was developed and Finite Element Analysis (FEA) was performed to obtain the theoretical results. To evaluate the theoretical results, a scaled model was made to conduct both static and dynamic testes in the laboratory. The experiment results are consistent with the results calculated by FEA. It is proved that FEA is an effective method to predict shear lag effect and dynamic properties of bridges of this type.

The analytical method precludes the use of the standard flexure and interaction formula in structural analysis and as such is considered as an out of the box method and contrary to the traditional graphical method of solution. This paper will show examples of capacity curves for reinforced concrete and steel sections solved by the analytical method. The prediction of the capacity of a structural section in concrete or steel construction is based on the known stress/strain properties of these materials. For concrete the parabolic nature of the stress/strain is applied in a section while for steel the linear stress/strain up to its yield value is considered acting on the steel cross section. The resulting stress volumes will represent the forces and moments, which can be developed internally in a given section of concrete or steel. The calculation of these forces and moments is done using basic mathematics. Hundreds of equations have to be derived and programmed in Microsoft Excel spreadsheets. The variables are the dimensions of the section, ultimate or yield stress of concrete or steel, number, spacing and concrete cover to centers of reinforcing bars and position of capacity axis. The capacity curve is a plot of the axial and bending moment capacity of the given section. The civil or structural engineer will plot the location or locations of the set or sets of external axial and bending moment loads within the envelope of the capacity curve. These loads maybe composed of several possible combinations of loading such as those obtained in bridge design analysis. Where these points are located inside the capacity curve is the decision of the civil or structural engineer responsible for the design of the structural member. This is where his experience and expertise can be used for the safety of design.

A computational design method is proposed to assist structural engineers in designing optimal bridge and roof truss systems. The results presented show that the proposed design method is capable of increasing both the efficiency of the computational process and the optimality of the truss designs evolved. The method explores a diverse range of truss topologies and geometries, while also optimizing the member sizes. A multi-objective genetic algorithm is used to perform shape optimization in order to satisfy the conflicting objectives of minimizing volume, minimizing deflections, and maximizing stress. Instead of handling stress and deflection objectives as constraints, these design criteria are stated as additional objectives to be optimized. The concept of Pareto-optimality is used to determine a ranking of current design alternatives that guides the search process toward optimal solutions. To reduce the design time required, the proposed computational method is implemented on parallel computers. Truss designs obtained using the proposed method are compared to designs obtained by other researchers on a benchmark bridge truss design problem in order to evaluate the performance of the proposed method. The truss designs identified provide more optimal truss designs then reported in other research efforts, while still providing comparable search efficiency. The proposed method was also applied to identify near-optimal designs for a new roof truss design problem.

A system identification methodology that accounts for factors influencing the reliability of identification has been proposed in previous work. An important aspect of this methodology is the generation of a population of candidate models. An indication of the reliability of system identification can be obtained through an examination of characteristics of the population. This paper presents feature extraction techniques that provide support for this examination. We use data mining techniques such as correlation measurements, principal components analysis and decision trees. These methods are useful for estimating the reliability of system identification when the number of candidate models is high and when relationships between parameters can be approximated linearly.

This paper presents a novel Computational Intelligence (CI) approach to model construction labour productivity. A hybrid neural network combining the General Regression Neural Network (GRNN), Fuzzy Logic (FL) and Genetic Algorithms (GA) are used to identify and quantify factors affecting construction labour productivity and to predict performance. The essential features of the network are described in detail. Its reasoning capability, predictive behaviors, and advantages are discussed. The use of the network is demonstrated for an example project.

Performance of the different parties participating in a construction project, particularly engineering professionals, plays an important role in its successful or unsuccessful implementation. This paper presents a study conducted to investigate how project characteristics impact engineering performance in measurable terms. A comprehensive approach that benefits from the capabilities of fuzzy neural networks (FNNs), utility functions and the analytical hierarchy process (AHP) is specifically employed for such purpose. In this context, utility functions and AHP are integrated together to develop an instrument for measuring engineering performance, while FNNs are used to develop a connectionist structure relating engineering performance to its influential project characteristics. For practicality, the study is implemented in the industrial construction sector. The paper begins with a discussion of the topic of engineering performance and the conventional methods for its measurement in the construction industry. Following is an overview of the adopted approach and the analytical capabilities it has. Afterwards, the paper presents the details of the system used for quantifying the sought impacts in the industrial construction sector, including, the basic architecture of the system and the data sets used in its development. Applying the developed system in quantifying the impact of example project characteristics is also illustrated. Lastly, conclusions of the study are drawn.

Accurate and objective rust defect assessment is required to maintain a good-quality steel bridge painting surfaces and make a decision whether a bridge shall completely or partially be repainted. For more objective rust defect recognition, digital image recognition methods have been developed for the past few years and they are expected to replace or complement conventional painting inspection methods. Efficient image processing methods are also essential for the successful implementation of steel bridge coating warranty contracting where the owner, usually a state agency, and the contractor inspect steel bridge coating conditions regularly and decide whether additional maintenance actions are needed based on the processed data. Previously developed image recognition methods for painting rust defect assessment can be summarized as two: the NFRA (Neuro-Fuzzy Recognition Approach) method and the SKMA (Simplified K-Means Algorithm) method. The NFRA method uses artificial intelligence techniques to separate rust pixels from background pixels. The SKMA method segments object pixels and background pixels in a digitized image using a statistical method, called the K-means algorithm. Even if both methods pass through different processing procedures, one common thing is that they first convert original color images to grayscale images and further process the grayscale images. This article presents the application of previously developed image processing methods for painting rust defect evaluations and discusses their limitations under several specific environmental conditions which are often encountered while acquiring digital images.

The capability to automatically identify shapes, objects and materials from the image content through direct and indirect methodologies has enabled the development of several civil engineering related applications that assist in the design, construction and maintenance of construction projects. Examples include surface cracks detection, assessment of fire-damaged mortar, fatigue evaluation of asphalt mixes, aggregate shape measurements, velocimentry, vehicles detection, pore size distribution in geotextiles, damage detection and others. This capability is a product of the technological breakthroughs in the area of Image and Video Processing that has allowed for the development of a large number of digital imaging applications in all industries ranging from the well established medical diagnostic tools (magnetic resonance imaging, spectroscopy and nuclear medical imaging) to image searching mechanisms (image matching, content based image retrieval). Content based image retrieval techniques can also assist in the automated recognition of materials in construction site images and thus enable the development of reliable methods for image classification and retrieval. The amount of original imaging information produced yearly in the construction industry during the last decade has experienced a tremendous growth. Digital cameras and image databases are gradually replacing traditional photography while owners demand complete site photograph logs and engineers store thousands of images for each project to use in a number of construction management tasks. However, construction companies tend to store images without following any standardized indexing protocols, thus making the manual searching and retrieval a tedious and time-consuming effort. Alternatively, material and object identification techniques can be used for the development of automated, content based, construction site image retrieval methodology. These methods can utilize automatic material or object based indexing to remove the user from the time-consuming and tedious manual classification process. In this paper, a novel material identification methodology is presented. This method utilizes content based image retrieval concepts to match known material samples with material clusters within the image content. The results demonstrate the suitability of this methodology for construction site image retrieval purposes and reveal the capability of existing image processing technologies to accurately identify a wealth of materials from construction site images.

The mission of the United States Air Force Academy is to "inspire and develop outstanding young men and women to become Air Force officers with knowledge, character and discipline; motivated to lead the world's greatest aerospace-force in service to the nation." As both a university and a military academy, the faculty faces a unique challenge to not only develop cadets educationally, but prepare all of its graduates to be successful leaders in the nation's Air Force. The primary method the Academy uses for ensuring its graduates are prepared to overcome the challenges they will face as officers is embodied in the core curriculum. In the Air Force Academy's core curriculum, all 4400 cadets are required to take a minimum of 132 credit hours of courses in the humanities, math, science and engineering fields. One of these courses is Civil Engineering 210, "Air Base Design and Performance." Looking deeper, this class is divided into three blocks: 1) Environmental 2) Infrastructure and 3) Contingency Response. In both the second and third blocks, cadets participate in capstone projects that employ concepts they learned in the classroom including community planning, functional relationship analysis, Air Installation Compatibility Use Zones (AICUZ), contingency operations, bare base beddown, Air Base Ground Defense (ABGD), Base Damage Assessment Teams (BDAT), Minimum Operating Strip (MOS) planning, Alternate Launch and Recovery Surface (ALRS) planning, and Base Recovery After Attack (BRAAT) just to name a few. This paper will discuss the operational Air Force Geographical Information System (GIS) software interfaces that have been tailored to use in conveying the classroom objectives to educate and train cadets in Civil Engineering 210 to ensure Air Force Academy graduates are officers with the knowledge to "lead the world's greatest aerospace-force in service to the nation."

This paper reflects on the conventions of distance education that have mitigated against international students studying for qualifications in the real estate and construction sectors. It examines the opportunities that the global expansion of information and communications technology presents to the providers of professional education at distance. In particular it considers ways of taking the passivity out of the distance learning experience and replacing this with active learning that maximises the satisfaction that emanates from an enquiry led approach to scholarship workplace research and personal development. Specifically the paper explains the Learning Pools approach to structuring learning within a Virtual Learning Environment, which lies at the heart of the design for a graduate conversion course. It describes how this abandons the notion of simply reading to regurgitate knowledge in exchange for a qualification. Instead the approach adopts the principle of acquiring, developing and building knowledge that is tested and recognized in a qualification—a concept which is entirely appropriate for graduate development in the construction and real estate professions.

The Computer Revolution has completely revolutionized structural mechanics both in its theoretical basis ("Computer Shapes Theory") and in its practical applications. This must be considered when teaching this centuries-old discipline to architecture and civil engineering students. As before, these need to understand how the structures they design are expected to carry loads, but now they also have to know how to properly use the software tools they will encounter in practice. In fact, undergraduate students should first learn how to properly model real life structures so that the computer will provide meaningful results. They then have to learn how to extract from computer results the information which is relevant for structural design. The theoretical intricacies of structural analysis, i.e. today mainly of the finite element method, can be addressed later or, at least for architects, not at all. The ability to manually perform structural analysis computations is never needed. Computer programs, if specifically and properly designed tor this purpose, can become a useful tool for developing the feeling needed for structural design. We address here two questions: What should students learn when first confronted with structural design? How can they be helped by specially-tailored software? The computer program EasyStatics has been developed with these questions in mind.

This paper describes an Internet Virtual Classroom currently being used in the Department of Civil and Environmental Engineering at the University of Louisville. Currently, this classroom concept is used in three courses: CEE 320, Fundamentals of Structural Analysis; CEE 420, Matrix Structural Analysis; and CEE 422, Fundamentals of Steel Design. A physical classroom, equipped with 25 student workstations is used during regularly scheduled class time for team-based online activity. Work required of students outside the regularly scheduled class period is tightly integrated with in-class activity. A key reason for the success of the concept is the ability of the classroom offer online grading services, using software developed by the author.

Finite element computational methods have totally penetrated industry for analysis and design of engineered systems. Current university academic content now includes both expository undergraduate as well as graduate level academic courses. To reach the practicing professional, an Internet venue enables unfettered access to academic content in a totally time- and distance-insensitive modality via specifically developed websites. The established UT CFD Laboratory Internet website presents a fully functional environment for graduate course participation in the computational engineering sciences, widely spanning continuum mechanics, including comprehensive computer laboratory experiences. An overview of the organization and content of this Internet archive venue is presented.

Spatial and temporal multi-layered information is required to assess the natural hazard susceptibility in the mountainous regions. The manual method of data integration for targeting potential zones susceptible to these hazards is expensive and time-consuming. The aim of this study is to operationalise a working methodology wherein geo-environmental parameters are analysed to develop models for mapping avalanche and landslide-prone areas using remotely sensed data and Geographic Information System (GIS). This technique can be used for speedy generation and updating of the landslide/avalanche hazard maps of remote areas and strategically plan for the future developmental activities by delineating the potential zones and avoiding them while laying out new roads in this difficult terrain. The utility of this methodology for the collection, integration and analysis of spatially-oriented data, as well as in finding out the inherent relation between separate entities has also been highlighted for an existing hill road in the Manali-Leh Axis situated in the Lower and Upper Himalayan snow climatic zone. It is expected that the present paper will highlight the utility of temporal remotely-sensed data and knowledge-based Geographical Information Systems for collection, integration and analysis of spatially-oriented data, as well as in finding out the inherent relation between separate entities.

Snow avalanches threaten villages, roads and railways in most mountainous regions in the world. The extreme avalanche winters of 1951 and 1999 in Switzerland clearly demonstrated the importance of avalanche dynamics calculations, in preparing hazard maps for snow avalanches. Today's hazard mitigation strategies rely both on practical experience and avalanche dynamics models that predict snow avalanche descent paths, runout distances and impact pressures. This paper discusses the practical difficulties of applying a multi-dimensional numerical analysis tool to predict snow avalanche runout distances. The tool is embedded in a Geographical Information System (GIS) to simplify the specification of input and to help the interpretation of numerical results. Essential for an accurate prediction of avalanche runout is not only the flow friction, but also the specification of the initial release conditions — the fracture height and area. These are semi-automatically generated with the help of the GIS system. An advanced TVD numerical finite difference scheme then solves the differential equations that govern dense snow avalanche flow in general terrain. The primary results are pressure maps that define runout distances and the extent of avalanche danger. Two example calculations are presented. The first is an application of a single avalanche track where different combinations of release zones are discussed. The second example analyses the usefulness of protective forests to reduce avalanche runout distances over a large area.

All but very small disasters commonly lead to response at local, regional, state and federal levels. Coordination between these groups leads to many problems in communication, data sharing, and collaboration. Among other difficulties, they usually have separate command structures and different communication tools. Local fire and police often cannot communicate in the field. The disaster site is also a chaotic work area with constant assessment, response and reassessment based on new information and changing situations. Keeping all parties informed is made more difficult by the disaster itself. Existing communication systems are frequently damaged or destroyed in the disaster. This problem is compounded by significantly higher demands on the remaining infrastructure by local residents as well as the rescue, recovery and aid workers. Rescue workers in particular provide response that is often time critical. Delays or problems in communication can increase loss of life and further endanger rescue workers. Development and implementation of improved technology to ensure basic communication only addresses part of the issue. The rescuers, including specialists such as engineers, HAZMAT, and medical, need to receive and communicate larger amounts of current and accurate information among themselves and with the command structure. It is critical that the right information get to the right people at the right time without broadcasting too widely and causing information overload. It is very difficult to identify exactly the right people in such a fast-paced and fluid environment. Existing manual protocols are constrained in complexity by the human limits inherent in a manual system. The use of technology to automate the information management and distribution protocols would allow better informed decision making.

A generalized approach is described aiming at a public system for flood crisis management at rivers in which the public is deeply involved and then looking at a closed system such as managing crisis on a geotechnical construction site where most information is private. Web-based technology has been used as widely as possible to provide easy access at any time and from any place. This paper covers aspects of data, monitoring, alerting and information access. For crisis management navigation through information should be supported by appropriate tools. For the closed system at building sites an approach based on an information model is presented. The aspect of virtual crisis management is briefly touched.

This paper presents a mitigation model which can reduce or minimize adverse consequences when a water network suffers from significant water shortage resulting from physical destruction of critical facilities in water network. The model optimizes the water supply plan for water customers utilizing the information regarding the priority of water customers. Two different implementation engines based on Branch and Bound (BnB) and Genetic Algorithms (GA) are developed and evaluated using two representative water networks. BnB is a general search method for solving discrete and combinatorial optimization problem, which guarantees a global optimal solution while GAs are heuristic search algorithms in which the global optimality of the solution is not assured. A hydraulic network solver, EPANET2.0 is linked with these two optimization tools to test the hydraulic feasibility of candidate solutions. The performance of the two different engines is evaluated in terms of the quality of solutions and computational efficiency. The findings of this study indicate that the proposed optimization model can successfully reduce the consequences while meeting hydraulic constraints in water networks. In addition, as the size of the network increases, the use of the GA engine is preferred because it takes significantly less computation time than the BnB approach, while providing reliable levels of accuracy.

There exist a wide variety of computational tools for the simulation and design of exits. However, due to the scarcity of behavioral data, these tools rely heavily on the assumptions about human individual and social behaviors. Many of these assumptions have been found inconsistent or incorrect. This paper presents a multi-agent based framework for studying human and social behavior during building emergency evacuations. A prototype system has been developed, which is able to demonstrate some emergent human social behaviors, such as competitive, queuing, and herding behaviors.

Many researches and practices witness that there still are many problems, such as fragmentation, budget overrun, time overrun and high waste in construction process, most of which are supply chain problems. These problems are often caused by the lack of coordination between organizations in supply chains. This research regards construction supply chain as a typical multi-agent system and designs a multi-agent based multi-attribute negotiation framework for construction supply chain coordination (MANCSCC). This framework integrates the specialty agents (contractor agent, designer agent, supplier agent, owner agent, etc.) and service agents (coordinator agent, monitor agent, name server agent) into a multi-agent system through the Internet to improve decision-making efficiency. Since different members in construction supply chain have different preferences on decision-making attributes, such as cost, time, quality, safety and environment, a multi-attribute negotiation mechanism is established by describing the multi-attribute negotiation process and designing the multi-attribute negotiation protocol. The design of this mechanism is based on negotiation theory and utility theory and aimed at promoting the coordination between specialty agents. A prototype system is developed and tested on a hypothetical construction project. The experiment indicates that MANCSCC provides a solution to construction supply chain coordination.

Intelligent Software Agents can be seen as one of the future oriented research and development areas. Hereby, agents can be characterized and differed from other software applications by several attributes. According to their different abilities, several types of agents and consequently, various fields of applications can be distinguished. This paper aims to illustrate a general overview of software agents, their abilities as well as promising fields of applications. In the second part of the paper, parts of one expedient research project are presented in more detail. In this project software agents were applied to facilitate, accelerate and optimize the whole process of AEC-Bidding. The process in itself is transferred to a virtual marketplace.

A diversion weir is a headwork facility built across a river to raise water level and to divert water for various purposes, such as irrigation, hydropower generation, etc. In this study, a Windows-based, visual, and user friendly program named WINDWEIR is developed in Visual Basic.NET programming language for the optimum design of a diversion weir with sidewise intakes. The methodology used in the program is developed with reference to the design guidelines reported in the literature and in accordance with the common engineering practice. The program determines the overall dimensions and the total cost of a diversion weir. It also performs stability analyses. The program is relatively flexible such that a design engineer can assess various dimensions of the structure by performing quick successive test runs to achieve an optimum solution among various alternatives. An application is presented to demonstrate the use of the program.

This paper outlines an integrated framework for a building design system capable of automatically building code compliance checking. Most previous studies have focused on the processing of design codes for conformance checking. In this work, the author investigates 3D CAD (three dimensional Computer-Aided-Design) techniques to support automated code compliance checking during the design process. In particular, the paper addresses the following issues (1) Extraction of the knowledge from a building code document (e.g. International Building Code), and representation of the knowledge in a computer-interpretable format; (2) Data representation of building designs in a 3D CAD system. (3) Mapping building code information with building design information that enables the computer to assist designers with the automatic code compliance checking; and (4) Integration of the knowledge in building codes and the design knowledge into a computer framework. The proposed framework will be able to identify code requirements relevant to a particular building design and notify designers whether the design violates the building code.

In this paper, based on the traffic design and control theories and combined with the traffic flow characteristics in China, the classification of traffic design schemes were summarized using the methodology of Decision Support System (DSS). Then the function modules, data structure, core models of the Traffic Design Computer Aided System for Urban Road Grade Intersections (TDCAS) were expounded in detail. Finally, a case study was used to prove the practicability of the software.

In this research the basic algorithm of ART2 neural network has been modified for proper and efficient classification of vectors. In the basic architecture of ART2, the length of vectors is neglected. This causes error in sorting; parallel vectors with different length are classified in the same category. To overcome this deficiency, a virtual input neuron is added to consider vector length. The modified architecture not only considers the similarity of vectors direction but also considers the magnitude of vectors in sorting. ART neural networks are classified as unsupervised learning nets, a method is presented for supervised learning of ART2 without general changes in the basic algorithm. In this method ART2 net is used to automatic design of structural members. Finally this modified algorithm is used for design of a sample building structure.

This paper is based on a comparative analysis of some twenty-six intelligent building facades and sixteen large media-facades from a social-psychology perspective. Our thesis is that at the centre of the development of automated façade lies the industrial automation attitude that renders the eventual product socially less engaging and machinic. We illustrate examples of interactive media-façades to demonstrate how architects and interaction designers have used similar technology to turn building surfaces into socially engaging architectural elements. We seek opportunities to extend performative aspects of otherwise function driven double-skin façades for public expression, informal social engagement and context embodiment. Through this paper we intend to bring forth emergent concerns to designing building membrane where technology and performance should be addressed through a broader cultural position, establishing a continual dialogue between the surface, function and its larger human context.

A web-based camera (webcam) is expected to enhance construction site monitoring, which may result in better project control. However, in most cases, webcams are located on the outside of a building because their mobility is limited by cable wiring, thus occasionally the view of the camera is blocked as the project develops. If a webcam is integrated with emerging wireless network technologies such as IEEE 802 or Cellular Digital Packet Data (CDPD), construction professionals may be able to utilize the webcam to monitor interior construction operations without worrying about getting the network cables wired on the congested and dynamic construction job site. Especially, the CDPD technology should enable the webcam to transmit captured photos from any construction site as far as the cellular phone service is available. However, with the speed of CDPD (19.2 Kilobits per second), it would take as long as 6 minutes to send one Mega pixel digital image. One may ask if construction professionals could figure out operations implemented at the job site by observing a 6 minute interval time-lapsed photo set. How many mistakes should we anticipate when interpreting the time-lapsed photo set with this time interval? To what extent can the frame rate of the webcam be lowered for monitoring construction operations at the job site? To answer these questions, we then produced time-lapsed photos of brickwork at three different construction sites with various time intervals and investigated error rates in identifying construction crew's productivity using these time-lapsed photos. This paper presents a preliminary result of our investigation.

Most structures need a periodic repair for proper functioning as they age. Maintenance of existing structures would be best implemented when proper information of the structure is available. Structure repair also generates additional information, which should be kept and utilized for the next repair. Since the construction industry is fragmented, the process of maintaining information regarding infrastructure management is prone to be troublesome and may result in omitting valuable data. Web-based project information management has demonstrated the merit of central data repository in sustaining valuable data in a central repository and expediting data exchange. Emerging Web technologies such as Scaleable Vector Graphics (SVG) and ASP.NET inspired our group to develop a prototype application to test the merit of these technologies in sustainable infrastructure management. This paper presents the development of a simple 3D vector graphics engine by utilizing SVG and its potential application to the Web-based 4D Construction Information Management.

This paper discusses the advantages and challenges of using speech recognition on mobile devices, for field data collection and real-time communication. Multimodal and voice technology, for speech-enabled information retrieval and input, using mobile phones or handheld computing devices is explained. Multimodal technology enables more complete information communication and supports timely and effective decision-making. It also helps to overcome the limitations imposed by the small screen of mobile devices. The paper describes several prototype, industrial, mobile solutions developed for the field entry of data and real-time communication that utilize voice and multimodal interaction. In one of these projects, a field concrete inspector can enter inspection results using variable interaction modalities such as speech, stylus, or keyboard on a handheld device, or speech-only on a mobile phone. The author describes prototype applications developed, and presents several usage scenarios for field and maintenance applications, as well as for emergency response.

The 3D laser scanning is one of the exceptionally versatile and efficient technologies for accurately capturing large sets of 3D coordinates. 3D laser scanner uses a technique that employs reflected laser pulses to create accurate digital models of existing objects. For 3D survey, detection of pavement distresses, such as potholes, large-area utility cuts or patches, is possible application where laser scanner technology excels. The traditional surveying and evaluation of distresses on pavement are extremely rough and restrictive as it implies lane or even entire road closures. In the study, the accurate 3D point-cloud points with their elevations were captured during scanning and extracted focusing on specific distress features by means of a grid-based processing approach. The experimental results indicate that the severity and coverage of distresses can be accurately and automatically quantified to calculate the needed amounts of filled materials. This application is the first attempt and can assist pavement engineers in monitoring pavement performance and estimating repair funding.

Emerging reality capture technologies, such as LADAR and embedded sensing, have potential to increase the efficiency of inspectors by generating detailed data about as-built conditions that can be analyzed in real time and at a later time at an office. The data collected using these systems provide an opportunity to visualize and analyze as-built conditions on construction sites in a more comprehensive way. At the same time, some characteristics of the data collected, such as its size and level of detail, provide unique visualization challenges. Currently available software systems deliver some functionalities to support construction inspection tasks by enabling the visualization and manipulation of the data captured using these reality capture technologies. In this paper, we provide an assessment of some functionalities provided by a set of selected visualization software tools based on the characteristics of the data collected and to be visualized, and on the construction inspection process that need to be supported.

Health monitoring of large-span bridges mainly aims at continuously accumulated damages and thus damage detection is the core technique of bridge health monitoring systems. Any crack or localized damage on a structure reduces its stiffness, which will lead to reduction in the nature frequency and modification of the vibration modes of the structure. The damage detection is based on comparison of initial signatures (frequency, mode shapes and so on) of intact bridge with those of damaged bridge. To identify the damage in time, the sensibility to damage detection is the key factor. In this paper, a new damage index, W value, is proposed by comprehensively utilizing the existed indexes. According to the analogue analysis the damages of Wenhui cable-stayed bridge with finite element method, considering 3% noise which in order to account the measurement error, the index, W value could localize the damage precisely and its validity is verified. The numerical results show that the proposed index is convenient to be calculated and has highly sensible. This method can be used into a practical bridge health monitoring system to realize the damage identification early.

In this paper we study how to detect physical and geometrical heterogeneities of the civil structures by the resonance frequencies of the torsional vibrations of its separate elements. Defects in a material of the element produce the changes of the mass density and alter the values of the resonance frequencies of the free vibrations. The mathematical model is based on the linear partial differential equation for motion of elastic elements in the assumption of heterogeneity of the density distribution along its length. Using the separation of variables we reduce the problem to the calculation of zeros of the transcendental resonance equation and find the resonance frequencies of free torsional vibrations. Then we solve the inverse spectral problem: restoration of the density distribution along the length of element if the several resonance frequencies are known. This solution can be used for the non-destructive control. The given element of the structure is subjected to the vibrations. The location of the defect and its quantitative characteristics are determined by the deviations of the values for the resonance frequencies obtained in the certain moment of time from the corresponding perfect values. The simple engineering formulas for the location of the cracks and its parameters are derived.

Highway bridges across the United States constitute an infrastructure component that represents an enormous investment at the federal, state, and local levels. Although the poor condition of bridge structures has been identified, monetary constraints due to decreased and competing budgets prevent the complete rehabilitation and/or replacement of these structures. It is becoming increasingly important to use available funds in the optimal way. This requires the best strategies to identify, monitor, and ultimately repair, rehabilitate, and reduce degradation. This study provides an analysis aimed at identifying distinct and important subgroups of bridges. Stratified samples that represent these subgroups of general bridge types can then be studied in depth, and the findings would apply to the corresponding subpopulation of bridges of similar construction. In particular, such a representative sample of bridge structures could be used for long-term monitoring in order to learn more about the degradation processes and how these processes interact with different bridge structures, material types, and other variables that are associated with bridge performance. A latent class cluster analysis is used to identify similar groups of bridges based on a comprehensive set of variables that are found in the National Bridge Inventory database. Although computationally complex, the analysis provides a comprehensive decomposition of a selected portion of the bridge inventory into groups that are defined in terms of the multivariate relationship of attributes for bridges of the same material and structural type.

The explosive growth of databases related to bridge management activities may exceed the capability of our traditional decision-making process. As structures deteriorate, records of inspection, maintenance, repair and rehabilitation accumulate. The fields of structural health monitoring and wireless sensor network are booming, and those technologies can collect data of all kinds. The need for the seamless flow and management of information as shared, reusable asset is emerging. This paper focuses on how to integrate varieties of qualitative and quantitative data related to bridge management, and elaborates the universal architecture for information processing. The architecture consists of Bridge Markup Language (BridgeML) achieving scalability and interoperability, knowledge management application discovering useful patterns and rules from huge quantities of data, and the prototype system has been developed.

The term intelligent compaction is now heard often enough to make one believe that the method used for documenting the quality of hot-mix asphalt pavement has evolved to a more modern state than is actually the case. In fact, the current process for determining the density of an asphalt mat uses 1960's technology. The nuclear density gauge was a major break through in the mid-1960's and quickly became the state-of-the-art for measuring asphalt density. It revolutionized the asphalt paving industry because it allowed the owner of the project to check the density of the asphalt mat much more quickly than methods used up to that time. That ability, coupled with improved asphalt production methods led to tremendous increases in constructor productivity. Now, however, the owner rarely checks the density of the asphalt mat during the paving and compaction process. The responsibility for quality control (QC) of the paving and compaction process has largely been given to the contractor. This shift in responsibility comes at a time when the construction industry as a whole is faced with the worst labor shortage in history, limiting the number of qualified QC technicians and equipment operators. Recently, researchers introduced a patented system that, when mounted on a vibratory asphalt compactor, can render an asphalt density reading (in pounds per cubic foot) every one-second in real-time. Details of the system and its successes and limitations have been documented in the literature. This paper briefly describes the system and details the essential contributions made by computer hardware and software to a successful onboard asphalt density measuring system.

With the fast development of information technology, the construction industry is facing an increasing demand for communication between its globally distributed partners and inter-operation between independent databases. Considerable research effort and industry initiatives practice have gone into efficiently manipulating information within a company. However, recent surveys show that the inter-operation between companies is not adequately supported. Also, projects face problems of information overload, which leads to low efficiency in project information management. The Semantic Web has been developed as an innovative approach to the sharing and manipulation of information by both humans and machines. It weakens the boundary of information sources, enables computers to retrieve information in different databases, and conducts some reasoning, inference, and deduction to find the most relevant information. This is expected to facilitate content-based information management between databases and demand-based Web Services for project participants, thus enhancing the efficiency of information management. This paper introduces the concepts and applications of the Semantic Web in general and proposes a framework for applying it in construction project information management. The potential benefits and challenges of this application are discussed and an example is presented to demonstrate some of the concepts.

This paper describes a software paradigm for composing engineering web services. Software modules have been designed and implemented to facilitate the construction and integration of web services. The paradigm employs a distributed data flow approach that supports direct data exchanges among web services, and thus avoid many performance bottlenecks attending centralized processing. The performance and flexibility are further improved by using mobile classes to distribute computations within the service framework and to reduce the amount of data traffic by moving computations closer to the data. A system has been prototyped to integrate several project management and scheduling softwate applications. It is shown that distributed data flow, combining with the utilization of mobile classes, is an effective approach for integrating large engineering software services.

The planning process of a building is very complex. Many participants with different technical disciplines are involved and work on certain tasks. To manage the planning process the project leader has to organize participants, tasks and building data. For this purpose modern information and communication technologies can be used very efficiently. But these technologies require a formal description of the planning process. Within the research project "Relation Based Process Modelling of Co-operative Building Planning" we have defined a consistent mathematical process model for planning processes and have developed a prototype implementation of an application for modelling these processes. Our project is embedded in the priority program 1103 "Network-based Co-operative Planning Processes in Structural Engineering" promoted by the German Research Foundation (DFG). In this paper we present the mathematical concept of our relational process model and the tool for building up the model and checking the structural consistency and correctness.

Since 2003 the bulk of major UK construction project collaborative software providers have been working together to develop standards that will allow for project data to be transferred between vendor applications. Under the umbrella of the Network of Construction Collaboratin Technology Providers (NCCTP) , an XML standard for project exchange has been developed to address user concerns of stability and choice. Through extensive discussions between vendors, a series of object classes and their relationships were defined, describing the data commonly held within a collaborative system. Each participating organisation then extended their application to transfer project data to and from the standard. An extensive testing program between the member organisations showed that projects could be successfully transferred from one vendor's system to another. This paper presents the key aspects of the developed standard, document, user and security sections, and how the model addresses the user communities' requirements, of supplier confidence, data security and transferability. It then examines the impact that the developed standard will have upon vendors who provide collaborative software to the construction industry. Contrasting previous information exchange systems developed for these products, the wide industry support given to the standard ensures that it is applicable throughout all similar products.

Although integration has been a research subject for decades, nowadays we still see problem statements related to integration, which are also very similar to those discussed in articles dated a long time ago. One of the major differences between now and then perhaps is our collective experience in resolving the integration problem by using common semantic models, which is still a mainstream strategy and has resulted in many different types of industry standards. This strategy offers stability and data transparency, but requires tremendous front-loaded effort to establish agreements in terms of data semantics among various software vendors, which is proved to be very difficult to achieve. Besides, the fact that today people are still facing and seeking solutions to the same problem as researchers did decades ago, to some degree, indicated the limitation of this strategy. In this paper, in addition to the review of major integration approaches, the author discusses a hybrid integration strategy, which may potentially provide many benefits for applications such as those supporting dynamic or ad-hoc collaboration among business partners. This type of collaboration happens often in many areas of the AEC industry, such as large-scale capital projects.

The 21st century is the time for the construction industry to embrace new ways of working if it is to continue to be competitive and meet the needs of its ever demanding clients. Collaborative working is considered by many to be the basis for new management paradigms such as concurrent engineering and lean production and is essential if architects / design and construction teams are to consider the whole lifecycle of the construction product. Much of the recent work on collaborative working has focused on the delivery of technological solutions with a focus on web (extranets), CAD (visualisation), and knowledge management technologies. However, it is now recognised that good collaboration does not result from the implementation of information technology solutions alone. The organisational and people issues, which are not readily solved by pure technical systems, need to be resolved. However, approaches that exclusively focus on organisational and people issues will not reap the benefits derived from the use of technology, especially in the context of distributed teams which are the norm in constructions. Work currently being undertaken at Loughborough University aims to bring together the benefits enabled by the technology, with the organisational, and its people issues to provide tools and methods to enable high level strategic decisions to be made to implement effective collaboration. This paper reports on the initial studies carried out in the project, the literature review and survey in the topics of collaborative working (existing technologies and methods), organisational culture and change, implementing ICT into the organisation, and there effects on business processes.

Construction firms attempt to improve project performance by adopting technology. However, the advantages gained from technology utilization are still not clear. Lack of information regarding technology benefits has resulted in industry reluctance to implement new technology. Therefore, there are needs for studies that quantify the impacts of technology utilization on project success. One hundred and thirty-one completed projects from across the nation have each been assessed for the levels of technology employed on 58 different common project work functions. In addition, the projects have been assessed for the levels of overall project stakeholder success attained. This paper reports on relationships between integration/automation technology usage in the construction industry and project stakeholder success. Findings are presented and analyzed according to several data class variables, including industry sector, typical vs. advanced projects, project size, public vs. private projects, and greenfield vs. expansion vs. renovation projects. In addition, integration and automation technology findings are presented by project phase. The analyses indicate that levels of technology usage are positively associated with projects' levels of stakeholder success for certain types of projects.

The need for effective collaboration systems in the AEC/FM sector has long been understood. However existing applications have a number of limitations. In particular, they rely primarily on a static mode of information delivery and do not take into account the end-user's changing context and changing project conditions. This means that the need, in the construction project delivery process, for context-based information delivery is not adequately addressed. This paper addresses this and focuses on the role of the Semantic Web and wireless communication systems in facilitating context-aware construction collaboration. These emerging technologies enable the targeted delivery of project information to mobile construction workers and can be deployed at any stage of the project lifecycle. The approach adopted as part of the WiSeCON project, in providing AEC/FM mobile workers with access to highly specific data and services on an as-needed basis, is presented. The key considerations behind this approach and the potential benefits are highlighted and a prototype system is briefly presented to demonstrate the possibilities.

The paper describes the initial development of the data modelling and search, exploration and optimisation processes (SEO) of a Grid-enabled problem solving environment (PSE). This environment will enable a client to access coupled computational components sited at different centres of expertise. Each centre offers a data generation and analysis approach that aids a better understanding of the design domain whilst providing a route to the identification of appropriate high-performance design solutions. The intention is to support satisfactory, remote problem definition that leads to the selection and application of appropriate design search, exploration and optimisation techniques. This should occur seamlessly so that the client is unaware that these processes are to be undertaken at different sites. The intention is that the system will support clients with extensive knowledge of their design domain but little expertise in state-of-the-art data modelling and SEO processes.

The engineers of the industrial age created the transportation, water, power and other grids that provide the infrastructure of the civilized world. On the internet a new kind of grids are being set up - ones that are pulling together computing and communication resources to provide infrastructure for the digital economy. Civil engineers too can make use of this new paradigm of computing, not only to crunch through complex simulations but to use it as a collaboration platform for their virtual enterprise (VO) that is involved in the design, construction and management of products. This paper introduces the concept of grid computing, identifies the role grids could play in engineering processes, presents a high level architecture for grids based engineering services and tools, reviews it and defines the research and development issues. It is based on the results of an on-going European Union project InteliGrid - Interoperability of Virtual Organizations on a Complex Semantic Grid.

A detailed finite element model for plain concrete beams strengthened with externally bonded CFRP sheets was developed using ADINA a commercially available code and specific materials behavior models. The beams are modeled in full length in two-dimensions and all the thicknesses are included in the FEM input data. 2D-solid, plane stress eight noded quadrilaterals are used to model the concrete and CFRP warps elements, and the reinforcement bars and CFRP sheets are modeled as three node truss elements. Comparisons are made for load-deflection plots at mid span; loads at failure and crack patterns at failure. Modeling simplifications and assumptions developed during this research are presented. Conclusions from current research efforts and recommendations for further studies are included.

High strength concrete columns reinforced with concrete filled steel tube (HSCCRST), which is an ordinary reinforced-concrete column where there is a steel tube designed to be put in the core additionally, are used quite extensively in high buildings in recent years in China. In this paper, the general situation about earthquake-resistant behavior experiments of the columns is presented. Based on the experimental results, the numerical analysis of the sectional moment-curvature relationship for the columns is proposed using fiber model. Comparison of experimentally obtained ultimate sectional moments and those predicted by numerical analysis are given and reasonable agreement is observed. Additionally, effects of different parameters on the sectional moment-curvature relationship of the columns are studied with the proposed analysis method. The results of the experiments and analysis both indicate that the existence of concrete filled steel tube in core of section of HPC column plays an important role in improving its ductility and strength.

Today's flexible rockfall protection barriers have reached a high development stage. An extension of their maximum rockfall retaining capacity of momentary 3000 kJ requires a super-proportional effort. Corresponding numerical simulations now enable a more efficient development or optimization of new types due to a reduced number of expensive prototype field tests. In addition, the use of software provides the possibility to simulate projected barriers considering special load cases, which cannot be reproduced in field tests, as well as special geometrical boundary conditions for individual sceneries. The developed software FARO combines new approaches in simulating the single barrier components through discrete elements with main focus on the loosely connected net rings and the suspension ropes. The falling rock is modeled as rigid body using a special contact algorithm for the interaction with the barrier. This paper presents the numerical background of the developed software as well as its application. The quality of the obtained results is documented through comparisons with full-scale rockfall tests.

Full-scale fire tests have shown that composite floor slabs behave well in fires even with unprotected steel beams. The main reason for this favorable behavior is the membrane forces caused by large deflections in the reinforced concrete slabs. A tailor-made finite element program called SlabFem which takes membrane forces into account is being developed to investigate this problem. The main focus of this paper is on a new approach to model the flexible shear connection between the steel girder and the reinforced concrete slab. When the temperature increases the steel beams loose their strength if they are not protected and the shear studs get more flexible. This has a direct influence on the load carrying mechanism.

Archaeologists consider the Maya civilization to be a stone age culture. This misnomer is applied to a unique and long-lived society that achieved advanced levels of scientific advancement while Europe languished in the dark ages. During the Maya Classic period, 250 BC to 900 AD, these ingenious people developed numerous scientific and engineering achievements including the concept of the number zero, a calendar system that is more accurate than our present day calendar; and creation of ingenious engineering applications including the construction of a long span suspension bridge over the broad Usumacinta River at the Royal city of Yaxchilan. This 106-meter long suspension bridge would be the longest bridge in the world until Italian Engineers built a longer span over the Adda River. This lost landmark of Civil Engineering was jealously hidden for centuries by the mysterious rainforest. Recently the Maya bridge at Yaxchilan and other ancient structures were uncovered by the new breed of Archaeo-Engineer using state of the art forensic engineering techniques aided by computer modeling and simulation.

Canal models can be used to understand the hydraulic behaviour of complex irrigation networks. Numerical methods such as the finite difference (FDM), finite element (FEM) and finite volume methods (FVM) have become well-established tools in water and hydraulic engineering. While finite difference schemes are widely used in hydraulic engineering, they are not suitable for certain types of problems, particularly flows which exhibit strong discontinuities. These limitations can be dealt with by introducing shock-capturing techniques. FVM with shock capturing schemes applied to the shallow water equations is thus suitable for modelling a variety of flows, particularly the propagation of shocks and water level disturbances throughout an irrigation network. This paper describes an object-oriented implementation of the finite-volume based numerical algorithm for the solution of the 1-D shallow water equations. The model solves the hydrostatic St. Venant equations using an explicit FVM with a Godunov-type high-resolution shock capturing technique. The Riemann problem for the 1-D shallow water equations is solved using an exact Riemann solver capable of handling dry bed conditions. The model is developed for irrigation canal networks with an object-oriented approach using Java and MySQL as a back-end for effective storage and retrieval of the data. The model has been tested for mass conservation and ramp discharge tests. Further development and testing are in progress.

Small world networks recently have attracted much interest in studying the properties of networks. They were initially used for the study of social networks but recently have been shown to be relevant models in other application areas. However, when analyzing real complex systems, such as water distribution networks, there are a number of problems that make the analysis very difficult. In this paper, a small world network approach is applied for analyzing the efficiency of a real water distribution network. In order to apply such an approach to water distribution networks, a refined analysis method is developed and this is presented in the paper. The application of the developed model is demonstrated by means of simple case study that highlights how such an approach can provide useful insights into the efficiency analysis of water distribution networks.

In future, ecological aspects will play a major role for planning processes in coastal engineering. Coastal protection measures interfere with the environment, mostly restricting natural processes with sometimes undesired effects on coastal ecosystems. It is necessary to have appropriate tools to estimate these influences. In this paper, a numerical simulation model which describes hydro- and ecological processes is presented. This consists of a discrete ecological model based on a Cellular Automaton and a hydrodynamic finite element model component. Possible transfer strategies, which allow a direct coupling between these different model paradigms, are presented. Main effects and possible influences on a changed hydro- and morphodynamic are shown with first academic tests. At last, an asynchronous parallel implementation for the efficient parallel computation of the Cellular Automatonist introduced.

An integrated surface- and ground-water simulation model has been used for managing regional wellfields in the north-central Tampa Bay area. However, this regional groundwater model, which covers about 900 square miles, with coarse spatial discretization is not well suited to provide accurate prediction of short-term changes in groundwater levels at specific monitor well locations. The accuracy of such short-term forecasts is crucial for optimization-based management models where average weekly changes in water level can be in the same order of the simulated error. Artificial neural networks (ANNs) are presented as alternative models that are capable of providing accurate water level forecasts. These ANNs are designed to mimic the governing physical equations with proper initial and boundary conditions. Furthermore, the ANNs take into consideration the short term memory properties for the relevant time series. Results demonstrate that, with readily available data, ANNs can provide highly accurate short-term forecasts for few days to a few weeks into the future.

NEES (the George E. Brown, Jr. Network for Earthquake Engineering Simulation) is a national, networked resource for next-generation experimental earthquake engineering research and education in the United States. The goal of NEES is to support open access to and use of NEES's facilities and data by the earthquake engineering community. The system infrastructure to support the NEES activities is the NEESgrid which is intended as a distributed virtual collaboratory cyber-infrastructure for earthquake experimentation and simulation. This paper describes an effort in developing reference data models for NEESgrid shake table experiments and large scale structural testing. Data models provide the semantic information describing the project and experimental data. Brief description of the data models and some of their features are presented in this paper. The proposed reference data models are shown to be flexible and extendible. Validation and usability of the reference data models have demonstrated that the data models are sufficiently comprehensive to save and organize the experimental data from typical earthquake engineering simulations.

This paper presents a university-industry joint research endeavor to apply simulation modeling to review, assess, and improve the current construction practices. In particular, the Simplified Discrete-Event Simulation Approach (SDESA) and its computer platform, a systems modeling and simulation tool for rapid construction application development and a result of in-house research, were utilized on an ongoing 4.2 km long highway viaduct construction project in Hong Kong. The limited site space did not allow on-site storage of the bulky precast viaduct segments (i.e. segmental box girders). Any disruption in the precast segment supply would lead to a whole idle day on the contractor's side. Hence, the construction logistics and operations, spanning from the prefabrication, transportation, to site installation, warranted simulation modeling to achieve harmonious supply-demand matching and subsequent high productivity. The precast segment erection method was observed, modeled, and verified by comparison with the site records. Several alternatives to tackle the site inventory problem were then postulated, simulated, evaluated, and compared.

A high-tech-fab project requires sizable funds to initiate the acquisition of land, facilities, and construction work. In order to facilitate ramp-up time and shorten that of commodity to market, accelerating the fab construction and start-up time is one of the widely used methods. Accelerating fab construction always induces time-cost trade-off, and increases construction cost risk. But how will construction completed ahead of schedule affect a fab project evaluation? This paper constructs a two-phase model to explore the effect of construction completed ahead of schedule. Using mathematical economics, the paper derives the analytical solution and explains how early completion of construction will affect the components of NPV, both in the construction phase and the operational phase. Then it introduces the time-cost trade-off relationship in construction cost and different kinds of net cash flow profiles in the operational phase; the paper discusses its significant implication for the earlier completion of a high-tech fab. Illustrative examples of fab project are then simulated. How finishing construction ahead of schedule will affect the project economic evaluation are examined.

This paper first investigates the motivations for developing situational simulations for the construction management domain. It then summarizes the efforts by the authors involving the design and implementation of situational simulation environments. Finally, the third section of the paper discusses possible directions in which construction management research can be extended in this area.

In spite of the wide acceptance of Activity Cycle Diagrams (ACD) based simulation for research and teaching in the academic community, the use of simulation in construction has generally been random and sporadic. In contrast, simulation methodologies based on the process-interaction (PI) modeling paradigm have made significant impact on the manufacturing sector by bringing about tremendous cost savings and marked productivity improvement. This paper reports on the current progress made in the exploration of the possibility of adapting the manufacturing simulation approach to a simplified, valid construction simulation technique that caters for construction needs. The paper compares the ACD and the PI modeling paradigms, identifies the major differences between construction and manufacturing in terms of modeling requirements, and introduces an adapted PI modeling paradigm for construction simulation. The construction example chosen for simulation is earthmoving with scrapers, a process characteristic of construction operations. Conclusions are given on the general applicability of the adapted PI methodology in construction.

Inspections performed by code enforcement officials (building inspectors of a code enforcing jurisdiction) to confirm building code compliance are an important part of the home building production process. In 2003, an estimated 10 to 15 million code compliance inspections for residential construction were performed in various jurisdictions around the nation. The inspection process and its outcome have a significant impact on all the stakeholders, including city building departments, homebuilders, and trade contractors. This paper focuses on the inspection process in production homebuilding and provides critical analysis via a discrete event simulation model. The design of the simulation model is at the subdivision level and provides a mechanism through which a critical analysis of the process can be performed and waste due to inefficiencies can be identified. The simulation model has been developed in SLAM-II. Input data for the simulation model was obtained from municipal jurisdictions within the Phoenix metropolitan area. Key output parameters include inspection failure rates, impact of failure rates on the production cycle time, and impact of inspection failure on resources provided by individual stakeholders. Even though the model is developed at a subdivision level its results can be extrapolated at the city level and broad conclusions can be drawn.

Discrete system simulation has been used to plan and analyze construction processes for over three decades. Many successful applications have proved its effectiveness. Despite the widespread applications, simulation has not yet been used to its maximum potential. There many reasons for this and the first is the difficulty in detecting modeling logic errors in the development stage, while the second is that the analysis of simulation result is wearisome, as the result is usually not enough intuitive. In addition, most simulation tools lack the capability to manage vast amounts of data involved in the simulation process. This is especially true with the spatial data. All these deficiencies dampen a project manager's desire to utilize simulation tools. In this paper a Geographic Information System (GIS)-based visual simulation method, in which system simulation techniques are integrated with visualization techniques, is presented to overcome the above-mentioned limitations. The corresponding software, GIS-based Visual Simulation System (GVSS), was developed. GVSS is a powerful planning tool offering visualizing and querying capabilities simultaneously. A real hydraulic and hydroelectric project in China named Nuozadu is systemically investigated using GVSS. Combining simulation with sensitivity analysis, GVSS determines the optimum equipment set schemes. Construction schedules are established. Successively, the reasonability of project schedule is verified by analyzing the intensity of the excavation and traffic flow. Finally, the complex construction process is dynamically demonstrated by 3D animation, which is a powerful tool for quick and comprehensive understanding of the complicated process. It is concluded that the GIS-based visual simulation methodology and the software GVSS are very helpful and useful for the design and management of the construction process. The analytical results have been adopted by the Kunming Hydroelectric Investigation Institute of China.

Dynamic behavior is one of the most important design considerations for high-rise structures; natural frequencies and corresponding mode shapes are basic data for seismic and wind response analyses. The final results of the analysis and design depend very much on the quality of the three-dimensional (3-D) finite element model developed. Comparison of natural modes of the mathematical analysis with those of field measurements is the most widely used approach to assess the credibility of the mathematical model. Finite element model updating of high-rise structures, a very time consuming procedure to achieve the credible model, has rarely been studied before. Different from the most popular model updating approaches which are based on sensitivity analysis techniques, this study presents an application of finite element model updating of high-rise structures with a computer aided model updating system (CAMUS). After investigating knowledge and experiences of model updating techniques and finite element modeling of high-rise structures, a knowledge-based system was developed to implement finite element model updating of high-rise structures. Based on the correlation analysis results of natural frequency that are stored in the knowledge base, the system searches the most likely error in the model over the knowledge base of possible problems and guides the user to update the model. The performance of the algorithm was demonstrated with an application of finite element model updating of a 66-storey frame-core wall office tower.

Information technology in construction (ITC) has gained wide acceptance and is being implemented in construction research as a tool to assist decision makers. Most of the research into visualization technologies (VT) has been into the wide range of 3D and simulation applications suitable for construction processes. Despite its development with interoperability and standardization of products, VT usage has remained very low when it comes to communicating and addressing the needs of building end-users. This paper argues that building end-users are a source of experience and expertise that can be brought into the briefing stage for the evaluation of design proposals. It also suggests that the end user is a source of new ideas promoting innovation. Psychological evidence suggests that the experience and expertise of end-users is developed over time through their continuous interaction with particular building spaces for living and working. This expertise can be accessed by means of visualization technologies. Many authors have shown the benefits of using VT with people who have not developed further their spatial skills, or do not have an architectural or engineering background. The interaction that a non-spatial specialist will experience when tested with a visual environment (VE), should stimulate his/her memory and recollection associated with a particular setting, and so enable an opinion to be formed. Previous research on work environments suggest that individuals have been studied only in terms of the association they have with the environment regarding satisfaction and performance. The subjectivity of these terms impedes the quantification of tangible factors. In this research a methodology that includes the comparison of VT and the traditional 2D methods is proposed. It will help to identify how much, if anything, a non-spatial specialist can gain in terms of understanding of a particular design proposal presented, using both methods.

Urban planning is a complicated process that includes several participants. The acceptance and the development of a new proposal require close collaboration among these parties. Collaborative virtual urban planning provides great opportunities to support cooperative work among geographically separated participants. Recent advances in the computer technology now provide chance to carry out the planning process collaboratively. This paper presents the n-Dimensional (nD) modeling approach to support collaborative working in the urban planning process. The paper argues that an integrated urban database, which brings together various data sets, is needed to support the collaborative urban planning process. The paper will present conceptual models being developed to represent GIS data, building data and various kinds of environmental simulation data in the nD database. Early experiences in using these data models to develop an nD modeling database to support environmental simulations will also be discussed.

This paper presents research that led to the design and implementation of efficient interference detection methods that can be used to identify and report undesirable conflicts that occur among static (e.g. structure in-place, idle equipment), dynamic (e.g. active machines and workers), and abstract (e.g. hazard spaces) construction resources in 3D animations of discrete-event simulation models. The designed methods are implemented in a software tool called C-Collide that integrates as an add-on with the VITASCOPE visualization system. Common types of clashes that can occur on real construction sites and that C-Collide can identify beforehand in 3D process animations include 1) intersection among physical in-place components (i.e. design interferences), 2) intersection among in-place components, components in transit, and/or pieces of moving equipment during construction (i.e. constructability interferences), 3) craft interferences and accidents (e.g. collision between two pieces of equipment operating in the same area), and 4) space intrusions (e.g. any resource—worker or equipment—encroaching arbitrarily shaped hazard or protected areas of the jobsite). Animations of simulated construction processes are computationally demanding because elapsed visualization time is always related to the elapsed wall clock time by a distinct viewing ratio. This viewing ratio must be strictly maintained regardless of the number of screen updates between subsequent simulation time instants. Thus, to depict smoothly moving scene objects and to avoid jerkiness in the presented graphics, the screen must be updated at an acceptable refresh rate (ideally >= 24 fps). The impact of the collision detection computations on this frame rate must thus be minimal. Computational efficiency in the designed interference detection methods was therefore of paramount importance in C-Collide. In addition, this efficiency could not be traded off against accuracy. In order to achieve this, the authors capitalized on advanced documented algorithms for efficient collision detection between arbitrarily moving 3D geometric objects to design mechanisms for interference detection, control, and response in construction process visualizations. C-Collide's interference detection capabilities dynamically check each motion of VITASCOPE scene objects to determine if any pairs of scene objects interfere undesirably. This provides a lucid understanding of all object motions and potential interferences in any area of activity on a simulated construction job site.

Geotechnical problems have become more complex as we utilise every spare inch of the ground in urban environment. We need to improve our understanding of the ground behaviour in any underground works and to have more comprehensive, but accessible, techniques to analyse these problems. Ground movement prediction has become more important in such urban development and the need to incorporate advanced non-linear small strain constitutive model in complex soil-structure modelling has become the norm of the industry. Designers are now familiar with complex two-dimensional (2D) finite element (FE) analyses with highly complex soil models. However, three-dimensional (3D) analyses involving soil-structure interaction problems have been limited to large projects or projects involving fund-rich clients because of the high cost and long computation time involved in undertaking such analyses. Others have attempted such analyses by making many simplifications in order to minimise the size of the problems being investigated or even utilising technique involving the use of multi-processors in their computation. This paper presents some examples where full 3D modelling undertaken using a standard PC was used to solve routine geotechnical problems using a state-of-the-art non-linear small strain constitutive model.

Traditional finite elements are based on simple geometrical elements such as edges in the one-dimensional space, triangles and quadrangles in the plane as well as tetra- and hexahedrons in the three-dimensional space. The extension of the geometrical basis to any polyhedron is enabled by the definition of a local coordinate system called the natural element coordinates. The formulation of interpolation and test functions in natural element coordinates enables the formulation of generalized finite elements. The differentiation and integration of these interpolation and test functions are essential for finite element approximations. In the paper convex and special non convex polyhedron are considered as geometrical basis for generalized finite elements as well as for the formulation of interpolation and test functions on natural element coordinates. Furthermore, methods for the numerical differentiation and integration of functions on these generalized finite elements are introduced. The paper closed with two applications in the range of fluid mechanic and structural mechanics.

Ongoing research at UMIST commenced in 1997 has resulted in the production of ProCost, an early stage building cost modelling tool. The software is based on Artificial Neural Network technology to produce single figure estimates of the total building cost. Recent research has however indicated that cost estimators cannot nowadays rely on single figure cost estimating techniques. This initiated the next stage of the research, which involved the investigation of subdividing the single figure cost output into a cost for each building element. In order to proceed, a large database of 360 buildings with developed elemental cost breakdowns was formulated with the aid of Building Cost Information Service (BCIS). This database was used to investigate the way that a series of building characteristics affect the cost of building elements. In order to model these relationships, linear regression analysis was used. The results of this method are discussed in this paper. Artificial Neural Networks, are then proposed as an additional way of modelling the data, and their advantages over regression analysis are considered. This paper presents the results of an extensive piece of research with respect to ProCost and discusses its evolution into a powerful cost estimating package.

Conceptual models are an essential part of research, especially where multidisciplinary teams need multiple models to capture and convey the disciplinary views. Here the authors present a reusable pattern that describes an effective means of operating within a multidisciplinary group to develop software. Patterns for repeatable processes provide savings in time. The quality of resulting products is higher, for the patterns have previously been used and the bugs have been ironed out. Examples here are from an active project in which the authors are developing simulation software for social scientists and security experts to analyze building evacuations. The team is comprised of engineers, computer scientists and social scientists. The paper gives justification for the use of patterns and a description of this process pattern in the context of the evacuation project. The process pattern includes: project description, construct identification, diagramming, construct mapping, spiral model for process iteration, interdisciplinary literacy, and special issues in the software environment.

Land border ports-of-entry (POE) are critical in both national and regional terms. By offering legal and safe crossing points, they help integrate people and economies between nations. As security continues to take a more prominent role, the impacts of periodically heightened security measures generate substantial short-term and long-term impacts on economy and social-demographic activities on border cities. Such impacts have not been well understood as most prior studies apply infrastructure component based approaches without a broader view of spatial and temporal impact of the POE on the regional infrastructure. This paper discusses the development of the multi-resolution large-scale vehicular traffic simulation and assignment model to enhance this modeling capability. The utilization of mesoscopic/microscopic modeling techniques integrates the simulation-based queuing and regional traffic simulation assignment approaches. Empirical results highlight the capability of the developed model in capturing the dynamic interactions of a complex transportation system.

The construction industry is the largest simple production industry in the United States. The importance of the construction industry is not limited to the United States. The construction industry plays an important role in the economy of many countries around the globe. However unlike other sectors of the economy, the construction industry is characterized by slow adoption of new technologies. One of these technologies that has not taken an important role in the construction industry is Distributed Virtual Reality (DVR) environments. There are many reasons that justify the slow adoption of DVR environments in the construction industry. One of these reasons is the lack of understanding of the possible uses of DVR environments within the construction industry. This paper summarizes a variety of possible DVR applications within the construction industry. These DVR applications are framed within one of the most common responsibilities of construction professional—scheduling. The DVR applications presented in this paper are intended to sparkle implementations in future construction companies. Therefore, this paper follows a descriptive methodology. This methodology is used because the main goal is to illustrate the potential applications and impacts of this technology in the construction industry. Since DVR applications have not been widely implemented in the construction industry, there is a dearth of statistically significant data to support the benefits of this technology. However, the results of the early developments of this technology summarized in this paper exemplify the potential impacts of DVR environments in the construction industry. Therefore, the DVR applications summarized in this paper have the potential to help construction industry to think outside the box and push the envelope to move into the future construction industry.

Improving and supporting the process of design knowledge reuse in the architecture, engineering, and construction (AEC) industry can lead to corporate competitive advantage. Whereas internal knowledge reuse from one's personal experiences is very effective, external knowledge reuse from an external digital or paper archive often fails. Based on a formalization of the internal reuse process from ethnographic studies, a prototype system, CoMem (Corporate Memory) is presented, which supports the reuse process, i.e., finding and understanding. This paper presents a usability testing framework and methodology and a usability evaluation of CoMem using formal user testing. The key dimensions for the usability testing are the size of the repository and the type of finding task: exploration versus retrieval. The usability evaluation results are presented and discussed.

Spatial and temporal data sets, and static (planned) and dynamic (actual) data that stem from temporal data, are constantly produced throughout the project lifecycle. The integration of these data creates various project metrics, which can accurately depict actual and anticipated project performance. Various 3D model-based project management systems have been introduced into AEC projects. However, these systems have been limited in their ability to visualize inter-related multiple data sets concurrently due to the fact that an adequate visual representation method had yet to be developed. This research introduces a 3D model-based visual representation method utilizing the power of information technology. The proposed representation enables the users to show a holistic picture of a project by applying the multiple project data sets to the geometric attributes (such as shapes, faces, and edges) of the 3D building model through color- tone variation and motion. The new control system is presented as a suite of 3D model-based data visualizations controlled from a user console, the Project Dashboard. The Project Dashboard introduces a new paradigm of project monitoring systems to project managers by providing intuitive information-delivery interfaces beyond the existing management and control systems.

Technological advances in personal protective equipment have improved the safety of workers in the construction industry. Even with such improvements, construction continues to be one of the most dangerous industries in the U.S. economy. Structural steel workers and construction laborers have two of the most dangerous occupations in the United States with 58.2 fatalities and 27.7 fatalities per 100,000 workers respectively. About 33% of all fatalities in the construction industry are related to falls, but in steel erection, 63% of the fatalities are the result of falls. As demonstrated by these statistics, there is a need for improvement of safety in steel erection. The purpose of this paper is to present a methodology for using Virtual Reality (VR) technology to improve safety in steel erection. VR technologies have been used in various fields for worker training, safety training, design evaluation, and military training. This paper outlines possible applications of VR for safety training in steel erection. One of the primary benefits of this application is that workers can experience simulated hazards like they would encounter in steel erection without real risk of injury.

4D visualization has shown some potential benefits for contractors, but few 4D tools are used in construction industry. This paper explores hindrances to use 4D technique in contractors' opinion, and then presents an approach to expedite the progress of using 4D tools. The approach which also integrates current CAD software provides a fast way to create 3D architecture and construction models from 2D drawings, and this approach can reduce a major hindrance of using 3D and 4D visualization systems. A construction case reveals application of 4D visualization conducing to increase contractor's advantage and to win the contract.

The complexity, tight budget, and dynamic market of today's construction project require the seamless integration of both design and construction data. However, despite the availability of both digital design tools (various CAD applications) and digital project management tools (such as schedule software and construction management software), design data has to still be entered manually into construction applications. In order to close this gap, CAD applications widely used in AEC industries are evolving toward providing the product data within the CAD package itself, in addition to the existing graphic-oriented data. While useful, those new data-driven CAD applications are largely design-oriented and are still hardly used directly in construction practices. In this research, a detailed case study is presented and analyzed to demonstrate the limitations of the current data-driven CAD application when used to support construction management. To address the limitations, a trade construction knowledge module using a specific product model is under development to provide domain views for different trades.

It is widely recognized that construction is information intensive and complex industry. Present trends in the construction industry have heightened the need for effective and efficient evaluation, monitoring and developing the actual physical progress reports. The use of 3D CAD in the detailed design phase of a project is rapidly growing which improve the design, drafting and constructibility of entire project. Photographs of construction site are a valuable part of documents and used by the consultants and contractors for variety of reasons. When field operation begins advancement of the work is monitored by measuring, capturing the digital images and developing the field progress at regular intervals. The 3D CAD drawings and 3D model developed from digital photographs can serve as a good communication medium by providing a visual representation of the exact status of the project. The aim of this paper is to identify the techniques, which were used in the construction industry for monitoring and evaluating the actual physical progress, and discuss the DCM model. The Digitalizing Construction Monitoring (DCM) Model, an interactive system which integrates 3D CAD drawings (is being used increasingly as a design tool for construction projects) and digital images (is being used to provide accurate information needed to document as-built construction schedule). This research have made a practical attempt to automate the process of producing as-built construction schedule by applying modern photogrammetry techniques to photographs and integrating with CAD drawings. The applications of DCM model in monitoring the progress enables project management team to better track and control the productivity and quality of construction projects.

A cut and fill earthworks management system was developed based on 4D CAD and earned value method. The system is composed of a schedule management system, 4D CAD system, cost estimation system, and earned value management system (EVMS). LandXML was employed as the product model to represent terrain data, and IFC was used to represent the process model. We applied the system to a past actual earthworks project and demonstrated that it could facilitate enhancing the control and management of cost and schedule of construction works as well as incorporating the progress payment method effectively.

The successful integration of information in the construction industry depends on the degree of support for standardization efforts by industry and academia. The essence of the standards is to operate in a common denominator layer, which includes the language to share information between parties. However the main difficulty in exchanging information resides in relating two or more actor or participant's data representations from each of their sources. This difficulty makes it impossible to coordinate processes, exchange constraints, and manipulate information among the actors. Several approaches to cope with this problem employ languages, like PSL- Process Specification Language, and XPLD- Process, Definition Languages. The proposed approach revaluates the specification languages and uses a schema to model the processes, labeled semantic schemas, which mediate among each actor's data representation. The schema contains a semantic component that describes the processes requested by the actors. This approach uses an architecture that resembles database mediation, but the proposed architecture differs in the mechanism. The main advantage of this approach is that it will enhance the reusability of the schema for future repetitive transactions and for multiple actors. In this context, the objective of this research is to provide the necessary theory and understanding of modeling processes in the construction domain given schemas that mediate the semantics between data representations of the participants.

The use of Design-Build (D-B) is spreading among the State Transportation Departments (STD) in the United States as a method for procuring transportation projects. A primary reason for selecting D-B is a strong desire to shorten the total project delivery time. Texas has recently modified its legislation in order to allow state agencies to adopt D-B and other innovative project delivery methods. Previous research identified inexperience of STD personnel with D-B as a major obstacle to successful adoption of such methods. Existing procedures for traditional Design-Bid-Build (DBB) are inadequate to the new approach and can slow the procurement phase, endangering the desired time reduction. The knowledge of the activities to be performed during the procurement and their critical sequencing is a central issue in conducting projects under D-B. Lessons-learned from early applications of D-B can be beneficial through a widespread diffusion of the procedures across different state agencies and districts. Although many research studies have investigated the evaluation aspect of such procurement, much less attention been paid to the sequencing of activities to be performed by a STD between the go/no go decision and contract execution. This paper overviews findings from research analyzing lessons-learned during the procurement of two D-B projects in Texas: State Highway 130 (SH 130), and the State Highway 45 Southeast (SH45 SE). Using early lessons-learned from these ongoing projects, the researchers have developed a D-B procurement process model for delivering highway projects. These lessons-learned are subdivided into process-related and activity-related. Process-related lessons-learned were used in streamlining the process. Activity-related lessons-learned are grouped by task, and will be helpful in performing these tasks more efficiently on subsequent projects. In addition, this research suggests some requirements for computing support to facilitate this new process and to take advantage of the lessons-learned.

Excess resource idling can result in cost overruns, while low resource coverage or long lead-time in resource acquisition can delay the project schedule. Therefore, systematically managing this tradeoff is critical to ensure project delivery in time and within budget. In addition, to provide practically useful guidelines and tools, the dynamic construction process needs to be realistically represented. As an effort to address these issues, a model-based dynamic approach is proposed for construction resource management. The dynamics of construction progress and the tradeoff with resource coverage are identified. Then, the dynamic resource management model that has been developed using system dynamics is described. By simulating the model, the effect of resource coverage on project performance is quantified and policy implications are obtained for dynamic resource management. Finally, the use of the model as an automated tool is demonstrated.

In the Architecture/ Engineering/ Construction (A/E/C) industry, large projects are tackled by consortia of companies and individuals, who work collaboratively for the duration of the project. Such projects are complex and consortia members provide a range of skills to the project. The running of these A/E/C industry projects requires the formation of secure virtual organisations to enable collaboration. An important feature of the consortia is that they are dynamic in nature and are formed for the lifetime of the project. Members can participate in several consortia at the same time. This is a complex situation to support with software and the Grid will be an important infrastructure for such systems. The Grid is perceived as an addition to the existing functionalities of the Internet. This paper describes the design, development and implementation of a Grid-enabled solution to the Product Supplier Catalogue Database (PSCD) application, a software package, which brings together designers, suppliers and product manufacturers to work collaboratively for procurement in multiple consortia in a virtual environment. In this paper we describe our experience whilst Grid enabling the PSCD application using Grid middleware such as Globus and Java CoG toolkits and the development of software to support these three types of consortium. As the Grid is new and unstable in terms of the software and documentation problems have been encountered problems during the development phase.

Ratios were constructed relating the second lowest bid, mean bid, median bid, maximum bid to the low bid for highway construction projects in Texas to study if there are useful patterns in project bids that are indicators of the project completion cost. It was found that the value of the ratios tend to be larger for projects where the completed cost deviates significantly from the original low bid. Larger ratio values were found for projects that were completed with a greater than 20% cost increase and for projects that were completed with a reduction in cost from the original bid amount of 10% or more. Regression and neural network models were developed to predict the completed cost of Texas highway projects using the bidding ratio data. The input data used were transformed using the natural logarithm. Various combinations of the calculated ratios, as well as the project low bid were used as input to the models. The models tested produced predictions of varying accuracy. The models produced predictions that varied between having 41,02% and 54.01% of their test cases within 5% of the actual completed project cost. The model with the highest percentage of closely predicted cases was a regression model using the mean bid ratio, the coefficient of variation, and the low bid as inputs.

Linear construction projects include both discrete linear projects and continuous linear projects. Almost all of the existing simulation models for linear projects are based on the discrete simulation technology and cannot satisfy the modeling requirements of continuous linear projects. There is also a lack of effective optimization tools for continuous linear projects. The available optimization models are either unable to handle complex systems or are formulated only for discrete linear projects. This paper proposes an integrated simulation-GA (genetic algorithm) approach for better planning and scheduling of continuous linear projects. The combined simulation technology will be employed to accurately model different types of activities and relationships. To calculate the production rate of a continuous activity at any point in time, an equation was derived to account for the learning curve effect, and the chaotic function will be used to simulate the uncertainties and the correlations in a time series of points. Decision variables involved in the optimization problem include the number of crews, crew sizes and formations, start times, construction sequences, and slowdown/break rules. A GA model will be developed to help the project manager search for optimal decisions. The solutions generated by the GA will be evaluated though the simulation model.

The principal actors involved in the structural steel construction include fabricators, steel mills, engineer designers, specialty shops, and erectors. The fabricator is an organizer and provider of this construction service, who typically selects its material suppliers and subcontractors based on lowest quotes or based on past business relationships. The fabricator has to evaluate uncertainties in the upstream material supplies and construction services that incur additional costs which may result in higher than anticipated total costs. Suppliers and subcontractors selection is usually based on several criteria such as pricing structure, delivery record, product quality, and service. Frequently, these criteria vary because they involve trade-offs from one job to the next. The selection process is complicated further by the fact that some criteria are quantitative while others are qualitative. The study proposes a decision support model based on cost and activity-based performance using the analytical hierarchy process (AHP) to allow fabricators to conveniently evaluate and select their material suppliers and subcontractors based on their perceptions of the importance of each criterion. The expected result will be forming an efficient and effective project team and supply chain. The proposed model will also be applicable to other specialty subcontractors and general contractors.

On the process of producing structures factories of pre-fabricated concrete components face the challenging task of integrating the supply chain and the various departments within the company and, at the same time, to handle the uncertainties related to the assembling process on site. The increasing long distances to the construction site, the topography, the occurrence of rain, the often low level of skills among construction workers and a number of other factors affect the level of this uncertainty in Brazil. The challenge here is to produce with reduced waste, high quality and on a synchronized fashion where every resource gets on the exact time and quantity required by the production process. In order to achieve that situation the flow of information plays a key role in order to enable a lean flow of materials. The present research has investigated this issue on the largest factory of pre-fabricated components (precast/prestressed concrete structural elements) in Brazil. It has investigated the required information and, also, the information technology that could enable a lean material flow, with emphasis on the increase of process transparency. The analysis focuses on the information flow among design office, factory of pre-fabricated components and the construction site. The authors present the use of a web-based collaborative environment as a key strategy to promote higher level of transparency on the communication process within the case study.

To design a system serving the information retrieval needs of the construction industry, designers have to study what information construction personnel need to retrieve from various sources and in what kinds of formats. This research uses a detailed case study to specify and formalize the Use Case Models (user models) for construction personnel. This model helps the underlying computer systems to process user requests into performable pieces of system commands. The result of this research is a configurable and extensible DBMS design schema for construction management. The system presents the user with what they need. The Interactive User Interface thus developed also provides the user with the ability to extend their search to find to more detailed information.

This paper suggests that emerging IT will significantly alter the work practices of construction projects, and that corresponding changes to the construction project management practices are required. The paper focuses on enhanced information management processes, presenting an overall framework for information management, listing the types of IT systems and issues that could make up the IT environment of future construction projects, and outlining a corresponding organizational role in the form of a project information officer.

In this contribution, methods are presented, which allow an analysis of a collaborative planning process. An analysis is done by an analyst, who represents a project manager, planner or any other person, involved in the planning process. The overall success of a product strongly depends on the efficiency of the planning process. The course has to be set at a point in time where only diffuse knowledge of certain information is available. Making a decision at such a point usually has severe impact on the development of the ongoing planning process. Typically, the process goes on with time and the goal is to achieve optimal planning advances. The challenge is to find the interdisciplinary optimum, which usually is a compromise. In general, many methods, defining assessment criteria and support solving problems, are applied in the field of sensitivity analysis. Integrated within an analysis environment those methods help to identify if planning decision support is necessary and how it can be achieved in the best way. There are further multidisciplinary aspects which additionally increase complexity: (i) planning processes are managed by several, geographically distributed participants; (ii) prediction of consequences of planning decisions is not trivial in multidisciplinary groups; (iii) there have to be considered several viewpoints that depend on individual perceptions of involved participants. As a consequence, analysis tools must be designed for great flexible but have to be able to answer individual questions. The Analysis Environment (AE) is realized by an agent based approach. Agent technology emerged as extremely useful to handle flexible and generic communication and interaction on a very high level of abstraction. Therefore, the AE becomes highly flexible and extendable.

During the early stages of bridge design, the decision on possible reliable structural configurations bears on many considerations such as maintenance, aesthetics, durability, construction method (i.e. CM), and environmental impact, amongst others. Recent studies suggest that quality can be improved in Egypt if design and planning during the pre-construction phase are improved. Other studies performed on superstructure construction methods used in Egypt reveal that in 43% of the studied cases the method used was not the best solution. One of the reasons for that is the inadequate study of alternative construction methods. Triggered by such findings this paper attempts to develop an intelligent decision support system that helps both designers and construction professionals during the early stages of a project to evaluate alternative construction methods of concrete bridges in Egypt using the Analytic Hierarchy Process (AHP). Research findings suggest that the main criteria affecting evaluation are cost, duration, bridge physical characteristics, stake holders' objectives, characteristics of construction method, the environment, and external constraints. A cost model has been developed and benefit to cost ratio is calculated for each alternative method. The paper concludes by emphasising the importance of incorporating construction knowledge in the design process.

This paper outlines research being undertaken to develop new tools for investigating the opportunities integrated water management offers. With the engineering profession moving towards integrated design and management strategies for urban water cycle systems, the simulation models that are being utilized within the industry are becoming increasingly complex. Moreover, the number of decisions and objectives to be considered is growing and as a result traditional approaches, such as trial-and-error, for finding the most suitable approach become impractical. The presence of many conflicting objectives means that there is no longer one unique optimal solution but a myriad of solutions lying on the Pareto frontier. This work explores the potential for multiple objective optimization to identify the Pareto frontier and subsequent computer aided interactive decision analysis to explore the frontier. The paper presents a simple water supply case study in order to illustrate these concepts.

Rescheduling of production schedules of precast elements is often necessary due to various causes arising from both on-site and factory conditions. Ideally, rescheduling should take into account resource and schedule constraints both in the factory and on-site. The priorities and objectives of factory and site managers are likely to differ and may well conflict with one another. This paper develops a multiobjective optimization problem associated with the rescheduling of precast production and demonstrates the use of a genetic algorithm-based procedure to search for solutions. Results obtained from an example considering two objectives indicate that the proposed production rescheduling procedure can identify a Pareto-optimal front of good quality solutions which can be used to facilitate the decision making process.

Activity scheduling and solution of activity networks for longest paths are of paramount importance to construction management, for they provide construction management teams with fundamental knowledge about a project, its projected duration, resource utilization and cost distribution over time. The most widely used method in analyzing such networks and solving for longest (critical) paths in activity networks is the Critical Path Method (CPM), a deterministic approach that relies on forward and backward pass calculations that exhaustively traverse the network adding activity durations to path durations to arrive at the total network duration and thus the longest path in a network. The paper presents a methodology to arrive at critical path calculations in construction networks using Ant Colony Optimization (ACO) algorithms. Ant Colony Optimization is a population-based, artificial multi-agent, general-search technique for the solution of difficult combinatorial problems with its theoretical roots based on the behavior of real ant colonies and the collective trail-laying and trail-following of its members in searching for optimal solutions in traversing multiple paths. In essence, ACO is inspired by the foraging behavior of natural ant colonies which optimize their path from an origin (ant nest) to a destination (food source) by taking advantage of knowledge acquired by ants that previously traversed the possible paths and the pheromone trail these ants leave behind as the traverse the paths to optimal solution. In computer implementations of the ACO algorithms, artificial ants are agents and solution-construction procedures that stochastically build solutions by considering (1) artificial pheromone trails which change dynamically at run time to reflect the agents' acquired search experience, and (2) heuristic information on the problem/network being solved. The paper outlines the fundamental mathematical background of the ACO method and a suggested possible implementation strategy for solving for longest (critical) paths in construction schedule networks. The ACO virtual multi-agent approach is supplemented by a database management system and a custom software interface that allows for the merging of this artificial intelligence technique with more traditional critical path calculation (CPM) techniques. Algorithms, sample software interface, and sample case studies are also outlined. Finally, basic advantages and limitations of the ACO method are discussed and possible future research directions are explored.

The process of preserving and reconstructing historical buildings poses several specific questions and raises problems which must be solved in the planning and management stage of the building process — from questions of architectural and art-historical significance, via the future purpose of use of the building, links to the surrounding buildings, environmental questions, questions of cost, time analysis, and quality assurance problems. Many of these problems can be solved with the help of a computer model of the course of the rehabilitation and reconstruction of the building created by a construction technology network diagram. The CONTEC integrated project planning, management and quality control system based on these diagrams has been used for bidding, planning and managing the reconstruction process of several significant historical buildings in Prague and other cities.

More and more state and local communities are relying on maintaining, operating, and refining the existing infrastructure systems instead of new large capital programs to improve the performance of infrastructure. Therefore, it is important for every governing agency to plan effectively for rehabilitation of existing facilities within the constraints of the capital program. This paper presents a computer based tool called the Model for Infrastructure Rehabilitation Planning (MIRP) to help governing agencies plan, select, and make decisions on infrastructure rehabilitation. With a group evaluation module and a flexible evaluation criteria database, the Model for Infrastructure Rehabilitation Planning can evaluate the facilities for rehabilitation needs at five different levels: (1) technical/social evaluation including functional criteria and social/community/political criteria; (2) group evaluation that allows multiple user evaluation; (3) cost evaluation, which includes cost estimates for partial and full rehabilitation of facilities with respect to functional and social/political criteria; (4) funding sources and constraints; and (5) management considerations. The paper also describes the software package and illustrates a hypothetical example to explain the model and software.

Engineers and researchers have focused on developing materials, methodologies for new buildings and construction in recent years. There is not enough attention devoted to infrastructures that have been constructed. The aim of this paper is to present a decision-making framework system for selecting an optimal structural rehabilitation alternative for infrastructure systems considering sustainability. Emphasis is placed on how to properly decide the degree of end users' second-time investment of their structures implementing life cycle costing. Life-Cycle Cost (LCC) Analysis has not reached maturity and therefore has not yet become a standard method that can be implemented universally. This paper presents a user-friendly spreadsheet application demonstrating that the Life-Cycle Cost Analysis can be performed with very minimal input. On the sensitivity study of the model, it is concluded that the discount rate has minor impact on the rehabilitation decisions once the discount rate is greater than 7% and the rehabilitation timing is crucial to a successful saving. The proposed spreadsheet package provides the engineers and owners with a quantifiable, close-form solution for selecting rehabilitation alternatives with very minimal input information required.

There is often a risk of structural collapse on refurbishment projects involving structural alterations, facade retentions and demolition. There is evidence which shows that the construction industry lacks appropriate management systems to cope up with the refurbishment safety risks and hazards. The decisions taken during the refurbishment process not only have an impact on the choice of material, level of safety achieved, but also a direct impact on health, safety and the environment. The domain of refurbishment works is ideal for the deployment of a decision support system as there are numerous safety problems leading to the conclusion that the management and technical solutions often adopted in these projects are inadequate and the required expertise and experience is often not present. This paper presents the development of a generic refurbishment process model based on the `Process Protocol' to identify the various activities during different stages of the refurbishment project. The developed refurbishment process model has then been used for the development of a practical Decision Support System for the project participants involved in a refurbishment project to avoid structural collapses.

Although Geographic Information Systems (GIS) are increasingly being used in the construction industry, there is very little evidence to show that such technology has been used in relation to issues to do with the labor force. GIS is able to integrate information efficiently, thereby placing planners in a better position to review, analyze and understand specific spatial problems. They facilitate improved understanding of the information, thereby leading to improved decision making. This paper presents a case study of how GIS is being used to facilitate the implementation of a labor market initiative aimed at diversifying the construction industry's work force. GIS is being used as a tool to facilitate the administration and implementation of the initiative, which is aimed at attracting under-represented groups in the industry such as women and ethnic minorities. The paper starts with a brief introduction to GIS and its current use in the construction industry before presenting an outline of how the GIS application is being used to facilitate the diversity planning initiative. On the basis of the case study presented, it appears that there is considerable scope for GIS to be used to facilitate data management and decision-making in relation to other labor market issues in the future.

Informatization has been becoming an effective and efficient measure for urban infrastructure management to heighten its effect. This paper defines urban infrastructure management and describes the framework of its informatization in the viewpoint of life cycle. On the basis of above definition and description, this paper presents the model of the informatization for urban infrastructure planning, construction, and management based on Web GIS and DSS, which involves the informatization for the infrastructure management of energy sources system, water resources system, communications system, posts and telecommunications system, environment system, and disaster-preventing system. Then the functions of the model are analyzed. Finally, as an example, informatization for the management of urban wastewater treatment infrastructure is analyzed to discuss the functions of above model. The applications of the model would heighten the management level of urban infrastructure, which would reduce the cost of urban infrastructure construction and maintenance, as well as improve its service level.

Materials handling operations on construction job sites are error prone and these errors might negatively affect labor productivity. According to a study by the Construction Industry Institute (CII), a set of well organized practices for managing on-site materials would conservatively produce a 6% increase in labor craft productivity. This paper describes a Pilot Test that measured the impact of Global Positioning System (GPS) technologies within materials locating processes on large industrial projects. Those processes were broken down in several steps. A direct comparison of the time traditionally invested in some of those steps and the time required when using GPS clearly determined the time savings associated with the technology. This study also discusses the feasibility of the technology deployment. Finally, the paper analyzes other potential positive impacts derived from GPS.

The implementation of a Decision Support System (DSS) in the construction industry involves many variables. The nature of the problem to be solved is the key factor, but the methodological approach to the problem, the DSS technique and the nature of the data available must also be considered. This paper presents a classification and analysis of DSS for the construction industry to help decision-makers choose the appropriate systems in the field of construction engineering and management. A rigorous content analysis was conducted on over one-hundred journal articles spanning over thirty years from the Journal of Construction Engineering and Management published by the American Society of Civil Engineering (ASCE). Five different taxonomies were applied to analysis the nature of the problem, decision, complexity, data-system and tool-technique. The findings show that DSS are mostly static, unstructured, and model-centric, and that simulation and suggestion techniques are the most used for the industry. In general, there are many ways of solving DSS problems in the construction industry, but the decision maker must strive to find the best solution for each specific problem. This study is intended to assist in the proper selection of DSS for a variety of construction engineering and management problems.

This paper presents a computer system supporting progress control. The system incorporates the knowledge of skilled construction managers about methods of forecasting the actual status and future status of plant construction progress. First, a construction site model is developed to forecast actual status and future status of construction progress using the current status of the construction site. For the construction site model, the input is factors that describe the status of the construction site, and the output is accomplishment and man-hours. Eleven factors describe the status of the construction site, including qualitative factors. For example, one of the qualitative factors is work efficiency. The factors are determined by analyzing the knowledge of skilled managers. The degree of influence between these factors, and accomplishment and man-hour, is determined by the Analytical Hierarchy Process (AHP) method. As a result, a method which can quantify the influence of these factors and forecast the variation of accomplishment and man-hour using this construction site model, is established. A skilled manager evaluated the values output from the computer system using this method, and the results proved that the system is effective for progress control.

There is an increasing need for effective tools for managing life cycle costs of civil products. These products range from large infrastructure systems, such as bridges and highways, to smaller items such as HVAC systems. The industry has expressed a need for collaborative systems for optimizing product LCC and for incorporating industry best practice into the optimization process. This paper presents a web-based semantic system for managing products' life cycle costs. The basic architecture of the proposed system represents costs as a hierarchy of cost elements. Each cost element has a dollar value that could be deterministic, probabilistic or fuzzy. Several indigenous and exogenous factors (also represented in hierarchies) can have a set of impacts on the values of these costs. Through the analysis of different impact possibilities and probabilities, a decision maker can study various alternative scenarios and define the optimum set of costs and their values. A set of web services are used to capture cost elements, factors and their impacts. A schema for representing industry knowledge regarding costs and factors that influence their performance. The semantic nature of the system allows for it to be an integral part of a corporate memory system, where decision makers will be able to document and access lessons learned about LCC optimization.

Change, a major cause of litigation, is inevitable and necessary to optimize a construction project. However, using litigation as the ultimate resolution is the last alternative for construction disputes, taking a huge amount of costs and time. To provide a tool, the Early Warning System (EWS) was developed by utilizing the Case Based Reasoning (CBR) approach. EWS is built to solve potential lawsuits caused by change orders using past resolutions based on data collection of this research. It was conducted in the basis of litigation archives stored in the Supreme Courts and appellate courts in 48 states and one district of the United States. 340 out of 4818 litigation archives were accepted as complete data samples during investigation. EWS is a useful tool to cope with unpredictable and unstructured disputes produced by change orders. It not only displays warnings when ongoing projects encounter similar situations occurred in the past, but also provides information related to past cases that contain procedures of settling disputes initiated by change orders. Finally this research contributes that construction owners and contractors can utilize EWS databases as reference to prevent unnecessary expenditure by legal actions.

Managing construction projects requires constant monitoring of project performance and follow-up schedule updates. With updated project performance data, project managers can take corrective actions in a timely manner, thereby mitigating any negative impacts on both the cost and schedule of a project. Among project performance data, productivity data from the field plays a key role in evaluating and predicting project performance in terms of cost and schedule. Despite its importance, most contractors do not take full advantage of the benefits of analyzing productivity data and proactively control a project. Although computerized systems are commonly used in the construction industry today, few project managers make full use of on-site productivity data to accurately predict future project performance. As a result, schedule delays and cost overruns are detected at a much later stage than they should be, causing costly fixes and overtime work. This paper presents the preliminary results of an on-going research that aims to develop a new approach to achieve proactive project control based on better prediction of project performance which utilizes time series analysis techniques with integrated historical productivity data and on-going field productivity. This research proposes a new methodology, named "Pro-Con", that extends the effectiveness of using productivity data that exists in most construction companies' computer systems. The paper presents the potential use of time series analysis in the construction domain to predict performance of a project in progress using integrated productivity data. Two case studies are presented to explain the methodology. The Pro-Con concept enhances field data processing and supports decision making for projects by incorporating up-to-date productivity data into existing project control systems.