AEI 2008: Building Integration Solutions

The role of university educators and administrators is to develop the most complete student possible through the educational process. This development should include intellectual competence, interpersonal competence, and the ability to create mature interpersonal relationships. Typically, engineering curricula have focused primarily only on the development of intellectual competence, therefore not addressing all student needs. The incorporation of problem-based learning and the use of teams in Architectural Engineering capstone courses provides an environment in which all of these development objectives can be achieved as well as an opportunity to teach problem-solving and team skills. When implemented in engineering capstone courses, problem-based learning can satisfy the developmental needs of students, the demands of employers hiring our students following graduation, as well as the criteria defined by the Accreditation Board for Engineering and Technology (ABET).

The increase of terrorist threats over the last decade highlighted the need to protect both civilian and military facilities from explosive accidents or hostile activities. We have observed an increasing need to protect against industrial explosive accidents, criminal activities, and social/subversive unrest. This problem may, in fact, exceed the previous reasons for addressing blast effects and protective structures (i.e., military-sponsored work on fortifications). Obviously, the future of engineering education programs has to be shaped accordingly. Careful attention must be devoted to typical modern civilian and military facilities whose failure could severely disrupt the social and economic infrastructure of nations. Therefore, military engineering cadets need to: 1) Know how to assess threats, hazards and abnormal energetic loading incidents. 2) Have knowledge of how such facilities (office buildings, schools, hospitals, power stations, industrial facilities, etc.) behave under blast, shock, impact, and fire loads. 3) Know how to design such facilities to protect lives and property. 4) Know how to conduct effective rescue operations and forensic investigations. This elective course on blast effects and protective structures is aimed at addressing a broad range of technical issues dealing with mitigating the severe loading effects associated with abnormal loading incidents (e.g., blast, shock, impact, etc.). This elective course will employ extensive course notes, references, various manuals, other handout materials, and a collection of computer applications to be used by cadets.

Construction phase is one of the important aspects of civil engineering structures. The success of a project depends on how well the construction phase is carried out. Efficient and economical construction is particularly important because of the increasing complexity of structures being built, the availability of improved materials and construction equipment. Typically in manufacturing field, robots are stationary and product moves along the assembly line. Automation is easier to incorporate because each product is identical with respective tasks done over and over. However, construction robots face with different demands than conventional industrial robots. They must move about the site, because buildings are stationary and of a large size. They require engines, batteries or motors and drive themselves. Construction robots also faced with changing site conditions and must be reprogrammed with each new condition. They must be able to function under adverse weather conditions including variations in humidity and temperature. Additionally, they are constantly exposed to dust and dirt on the site. Thus, there is a need to develop a robotic system for full-scale experimentation for realistic assessment of automation in the construction industry. This paper presents some aspects of robotization and automation and a case study is presented to demonstrate the applicability of robotics in construction industry.

There are currently 17 ABET accredited Architectural Engineering programs in the United States. This paper presents curriculum data for these Architectural Engineering programs and discusses the challenges of finding common ground and conveying program needs to the rest of the academic community — especially when the programs are so small in number and so diverse in their structure and course offerings.

Building Information Modeling (BIM) continues to transform the discipline of architecture, both in concept and practice, with the promise of streamlining the design and construction process. As opposed to 2-D CAD, 3-D BIM allows for almost limitless opportunities with respect to design, coordination and the sharing of information by architects and their consultants. The abstract nature of 2-D slicing is increasingly being replaced by full 3-D representations, allowing greater participation from stakeholders previously alienated from the building process. Similarly, BIM in architectural education continues to gain acceptance as a tool for demonstrating the comprehensive design abilities of students. 3-D representations of studio work, as opposed to traditional slicing in the form of plan section and elevation, allows for an increased depiction of the various systems employed and in turn a greater understanding of building tectonics and systems integration. While the application of BIM as a comprehensive design tool continues to be utilized, this paper examines where BIM may also serve as a transformative technology and methodology within the architectural curriculum at Montana State University School of Architecture, primarily as a tool for a greater understanding of building materials, assemblies and systems as well as for building systems integration and technical documentation. Through a review of the technical requirements outlined in the NAAB criteria for accredited schools of architecture, of the current curriculum and of the student outcomes over the past 4 semesters, this paper documents the successes and shortcomings of BIM integration in the technical course sequence at MSU. The goal of these investigations is to better understand the pedagogic value of BIM in architectural education specifically in the areas of materials, assemblies and systems integration and better prepare students of architecture to influence the inevitable paradigm shift from 2-D slicing to 3-D integration.

The rapid movement from Computer-Aided Drafting (CAD) to Building Information Modeling (BIM) by professional architects and engineers creates several challenges and opportunities for Architecture and Architectural Engineering programs. The BIM methodology offers dramatic new benefits to students that university programs have just begun to explore, but it also will likely trigger trade-off considerations for traditional skills that might be lost. Some educators worry that new BIM activities pose a threat to design thinking. This paper surveys some of the major challenges and opportunities that BIM presents in educational settings, with several suggestions for future directions for exploration. These findings are discussed in the context of several key conclusions that have been developed based on six semesters using BIM in junior- and senior-level architectural design studios in an undergraduate program in Architectural Engineering. The paper remarks on accreditation issues, and it seeks to develop potential ‘best practice' hallmarks with the goal of stimulating future discussion.

This paper investigates the computer aided drafting (CAD) to building information modeling (BIM) transition from the student perspective in an architectural engineering (AE) degree program at the University of Wyoming (UW). A sophomore-level architectural engineering graphics course introduces CAD as the primary means of design communications. The following two courses are introductory and terminal architectural design studios where BIM first intervenes. Then the senior capstone course in systems design reverts back to CAD. Several problems occurred along the way such as the finer details of working with the BIM software to bigger pictures issues of being introduced to BIM at different points in the curriculum. I performed a narrative research study in the auto- and biographical traditions to recount and construct our BIM experiences. We recommend to UW faculty that CAD should be kept in the curriculum, and BIM should be introduced alongside CAD in the introductory graphics course.

In the spring of 2006, Montana State University began to include a Building Information Modeling (BIM) program in its digital graphics and design curriculum. Since then, an increasing number of students have had the experience of designing with BIM programs and comparing their processes and final products with other students who are using traditional Computer Aided Design (CAD) programs. While 2-dimensional CAD and 3-dimensional BIM models may simply be tools to accomplish the same end, they provide two radically different approaches to learning architectural design. This paper discusses the implications of BIM with respect to the student experience. Within this topic, the paper describes the classes in which students are using BIM software and exactly how the experience of designing with BIM is different than the experience of designing in two dimensions. The paper also outlines the ways in which we can expect BIM to alter architectural education in the near term as well as in the future. Lastly, the paper addresses the concern that many have that Building Information Modeling hinders creativity. The paper concludes with some recommendations as to how BIM can be used to the greatest advantage in the classroom.

Motivated by the repeated damage to vibration-isolated equipment in almost all strong earthquakes that occurred in the past four decades, an experimental study was conducted to verify the adequacy of the current static method used for the seismic design of this type of nonstructural components. The study included earthquake-simulator tests of two HVAC equipment items supported by restrained vibration-isolators. The test results confirmed that seismic protection of vibration-isolated equipment by snubbers comes at the expense of amplified acceleration responses and dynamic loads, which are often much larger than those predicted by the static method. The differences between the predictions of the static method and actual dynamic responses of the equipment were attributed to four aspects not considered in the static method: Rotational responses of the equipment, nonlinear relationship between the gap size and seismic demands, effect of thickness and hardness of the snubbers, and effect of flexibility of the equipment.

The coordination of mechanical, electrical, and plumbing (MEP) systems has become a major challenge for building contractors. Specialty design firms and trade contractors, working independently, provide these systems. The coordination of these systems involves locating equipment and routing Heating, Ventilating, and Air-Conditioning (HVAC) duct, pipe, and electrical raceway in a manner that satisfies many different types of constraints. For the past several years MEP coordination has involved sequentially comparing and overlaying drawings from multiple trades, in which representatives from each MEP trade work together to detect, and eliminate spatial and functional interferences between MEP systems. This multi-discipline effort is time-consuming and expensive. With the recent development of Building Information Modeling (BIM) this process is now able to evolve with the software technology. Using examples from several case studies, this paper demonstrates how BIM can improve the MEP coordination process in buildings. The results of this research provide a foundation for a revised work process utilizing modeling software and information technology.

Over the past few decades, glass coating technology has played a key role in the advancement of curtain wall design. From reflective to low-emittance (low-E) coatings, the available range of materials has provided the designer with greater flexibility in the areas of aesthetics and thermal performance of curtain walls. One of the more recent advances has been in the area of anti-reflective (AR) coatings for glass. Initially intended for items such as eyeglasses and museum display cases, anti-reflective coatings are now being applied to glass in commercial storefronts and curtain walls. This allows for clearer viewing through the glass in applications such as building lobbies, shopping stores, and stadium press and sky boxes by reducing the amount of light that is reflected back at the viewer. This case study will focus on the technology and potential problems with AR coatings exposed to the exterior. The case study involves glass installed in a sloped curtain wall that clads luxury skyboxes at a large Midwestern stadium that was renovated within the past five years and included the replacement of all seating and construction of luxury skyboxes along the east side of the stadium. The case study investigation involved staining of the coating during construction, the composition and placement of the coating, and remediation options considered. Basics of coating types and technology will be discussed as well as actual field surveys and lab testing performed as part of the case study.

A ten-story downtown Chicago office building, built in the early 1970s, had been experiencing insulating glass unit failures, water leakage, and problems with occupant comfort. Several investigations in the 1990s concluded that the entire curtain wall system was deficient and required replacement. However, the office building houses the offices for the Social Security Administration's Midwest Region, and each month serves over 9 million beneficiaries. Disruptions to this operation would be catastrophic. Based on careful study and analysis of the existing curtain wall aluminum framing elements and connections to the building structure, it was concluded that the framing could be reused and was capable of supporting a supplemental cladding system attached to its exterior face. A pre-glazed unitized curtain wall system was designed which was hung to the original framing after the original glass was removed. This solution reduced the disruption to occupants, enhanced the speed of installation, and reduced the time period between deglazing and new cladding installation to a matter of days. The work was largely performed from the exterior of the building starting in the fall of 2007 and is scheduled to be completed by the spring of 2008. The replacement cladding has enhanced insulating glass, condensation control and water management; providing a cost effective solution to the client's problems.

The design and construction of buildings requires an immense amount of information. Yet, little is really known of the information flow in projects. This qualitative analysis studies the information flows for the design and construction of exterior wall systems. By investigating these needs, it was found that a large portion of the information that existed within the team was not being used effectively. Additional information needs that did not already exist within the project team, needed to be provided by outside sources. The process for effectively incorporating information from inside and outside sources was heavily influenced by: 1) interpersonal relationships between team members; 2) understanding the information needs of the projects at the system and whole building levels; and 3) use of various mechanisms to effectively communicating problems and possible solutions. Using ethnographic research methods, this analysis provides a much deeper understanding of the conditions of projects concerning information flow and the performance of project teams on information aspects of a project. The results show the importance of information flow to completing design and construction activities with the implication that managers need to assign greater importance to effectively managing information flow on highly complex projects.

To obtain stucco that performs its intended function, go beyond the industry standard by implementing high-performance solutions. 1) Follow the lead of other industries by working to standardize quality control test procedures for the various stucco components. 2) When designing the WRB, remember that it is essentially a waterproofing membrane. Pay close attention to sealing and flashing around penetrations, terminations, odd geometries, and transitions to other systems. Provide continuous solid sheathing to support the WRB, and include provisions that drain water out of the system. 3) Stucco cracks when tensile stresses overcome tensile strength. Reduce stresses in the stucco by preventing load transfer from the structure and maintaining hydration during cure. Increase the stucco's tensile strength with high-performance additives such as lime substitutes, polymer treatments, and fibers. 4) Avoid using premixed stucco products unless you know what's in them, how they've performed in the past, and who to contact at the manufacturer's office in case you have questions or problems. Even then, implement testing procedures to ensure that the selected product is appropriate for the particular project. 5) Gather information about the mix that the installer intends to pump at each project. Work in the industry to standardize pumpable mix designs, and test the mix onsite to check physical properties. The costs of implementing our suggestions will seem small when compared to the value gained and liabilities avoided by improving your project's stucco system.

This paper summarizes the findings of a pilot study to determine whether the type of drywall joint compound will influence the shear strength of wood-frame stud walls sheathed with drywall. In this study, five 8 ft x 8 ft specimens were tested under in-plane cyclic racking loading following CUREE loading protocol for light-frame wall systems. Three specimens were finished using non-cement based joint compound and the other two using cement based joint compound. Based on the limited number of specimens tested, the results show that the use of cement based joint compound on drywall joints as in the specimens tested will result in higher wall shear capacity compared to similar specimens finished with conventional non-cement based joint compound. The failure modes for the specimens finished with the two different types of compound were different. The result of the study is particularly important for high seismic regions where interior stud walls in residential construction effectively take part in seismic resistance even though wood shear walls are normally used on exterior walls.

Reinforced segmental retaining walls (SRW) have been shown to be a very effective earth retention system. Conventional reinforced segmental retaining walls use concrete blocks as their facial system, to which the earth reinforcing geogrids are attached. This binds the blocks and soil into one composite system. The use of FRP facial panels are proposed to increase the utility of reinforced SRWs by eliminating numerous structural problems faced by the conventional system. Reinforced SRWs pose complex structural questions due to the discrete nature of the blocks and the possibility of localized stress concentrations within the system. Moreover, computational analysis techniques are not easily applicable to reinforced SRWs due to the complex nature of the constituent elements. FRP panels could serve as a viable substitute for concrete blocks, and properties of FRP panel walls would be more predictable than concrete block walls, thereby, allowing a less conservative design. Furthermore, the use of the proposed FRP panels would allow significant cost savings and reduce construction time. The blocks that are used are rectangular in dimension and have a surface area of 1–2 ft²; an increase in block size would mean a reduction in construction time. The weight of the concrete blocks lends constraints to the block dimensions. However, using a different and lighter material for the units (i.e., FR polymers) would allow a larger size and would thereby reduce the construction time. To encompass all the aforementioned justifications, an FRP panel wall is proposed and its benefits are discussed. The article also compares the proposed FRP facial system to a concrete block facial system from structural and economical perspectives.

Investigation of concrete inhomogeneity of concrete fragments of cast-in-place skeleton-type buildings, which were produced simultaneously with the building vertical structures erection, is carried out. Ultrasonic pulse method and the method of sawing the full-scale fragments into experimental samples — prisms, with their following testing were used. The analysis of the revealed differences of density, strength and deformation characteristics of different zones of concrete column fragment is discussed and presented.

This paper gives the presentation of the author's experience with the use of carbon fiber reinforced polymer (CFRP) to rehabilitate and strengthen existing and new concrete structures. The various methods of strengthening of structures are first described. These include the external post-tensioning using high tensile bars or strands, the reinforced concrete jacketing, and the reconstruction of structural members. The paper describes the advantages of CFRP in its high tensile strength of 100 ksi minimum, its constructability, and its environmental friendliness. The process does not require demolition or closure of bridges or buildings that are being strengthened, as compared to some other methods. With good products and skills, the procedure of strengthening using CFRP wrap is simple and quick. The author presents his experience in evaluating and selecting an appropriate method for several cases under different conditions. These are the strengthening of existing reinforced concrete circular columns in existing bridges overseas and in the US, the strengthening of rectangular concrete columns in new building, and of new post-tensioned concrete beams, both by concrete jacketing and CFRP wrapping. Suggested procedure for application of CFRP is given, and final precautionary notes are given in the conclusion.

As a look of modern architecture design, the use of glass as curtain walls and window systems with different shapes has been quite up worldwide. The glass panel is not used only as a member for closing the space but also as a structural member for carrying loads such as wind pressures. As a result of using glass, new questions to the designer have been regulated in standards. Recently, a special test facility developed at Minufiya University, Egypt where laminated glass laboratory triangular specimens were tested under uniform lateral loads and simply supported boundary conditions. A previously reported model that used finite element methods with von Karman assumptions solved the glass ply problem. Both experimental and theoretical results compared and presented.

Historically, parking structures are perceived to be dark and dangerous places. Proper design of the passive security features within a garage, combined with appropriate active security measures, can create a welcoming, safe, and secure space. With features that deter criminal activity and promote safety, a garage will be well- received by the user, the community, and the owner. An explanation of security considerations for a parking garage is presented herein, including a discussion of garage lighting. Other security considerations include openness, visibility, access control, perimeter control, and electronic security measures (e.g. CCTV, intercoms, etc.). Active security, primarily consisting of manned patrolling, is also briefly discussed.

Applying security to campus buildings, warning systems, communication and computer network systems will greatly reduce the risks of hazards during network attacks, emergencies, and day-to-day operations. Today's campus heavily relies on computer network systems to function and perform most of their activities in teaching and research. As campus resources are connected to the Internet, the implementation of an effective security system becomes imperative. This paper outlines the risks of campus network systems and presents a survey of examining the practice of intrusion detection and prevention, which encompasses possible security aspects in a campus or an organization environment and the technologies to protect the communication systems from increasingly sophisticated attacks. Specifically, an integrated security framework has been introduced for protecting people, systems and information in the campus.

The "events of nine-eleven" were an awakening for all professionals involved in design and construction of buildings and infrastructures and emphasized the importance of providing a safe and secure accommodation for their occupants, their functions, and their missions regardless of location. Building codes and standards are currently limited in providing adequate guidance for the managers, engineers, and architects who are responsible and ultimately liable for protecting and assuring the integrity of the built environment. However, noble attempts have been made in more recent years to identify critical assets and to determine cost-effective measures for minimizing the impacts of a potential adversarial attack. In order to be assured that viable protective means have been taken, a systematic risk assessment and management approach has been developed that has been applied successfully to numerous critical buildings and major supporting infrastructures. This paper describes and demonstrates the application of a validated methodology by providing typical examples where the systematic approach has been used for high-rise buildings, for its supporting primary and backup utility systems, for communications and data centers, for adjoining parking facilities and building access systems, for security and fire protection systems, and for other critical assets that were determined as a requirement to maintain operations. A systematic building characterization and functional inventory initiates the procedure that establishes the usually numerous most-critical-assets. Subsequent steps further detail vital information such as: 1) how the threat scenarios are determined, 2) how the impacting consequences are evaluated, and 3) how the infrastructure vulnerabilities are identified so that justifiable and cost-effective protective counter-measures can be recommended for subsequent management decisions. The primary objective of this robust decision-support process is to evaluate and provide the "real data base" so that owners and managers become fully cognizant of all the technical and operational details that are vital for their continued building operation. The risk assessment information can then assist with determining where the appropriate protective strategies indicate that both a) the calculated risk reduction potential is possible, and b) an assurance that consequences (including the loss of partial or total mission, loss of life and injuries, and owner income-revenue) can be adequately mitigated in the event of a potential malevolent attack. Alternatively, all practical and conceivable contingency operations and recovery plans are revitalized and upgraded to minimize the impacts and damaging effects of any losses.

While statistical data indicate that risk of progressive collapse in buildings is very low, loss of human life and severe injuries would be significant when a fully occupied multi-story building encounters partial or total failure. As a result of recent terrorist attacks on buildings throughout the world, particularly U.S. owned and occupied buildings, and recent natural hazards like Katrina Hurricane; several U.S. government agencies with large construction programs have developed their own design requirements (GSA 2003; DOD 2005) to provide resistance against progressive collapse. Each agency, however, with its own mission, has adopted different performance objectives for buildings subjected to abnormal loads. Foundation and geotechnical design considerations to provide resistance against progressive collapse are important components of the overall building performance under abnormal loadings. This work discusses the role of geotecnical and foundation system design considerations to reduce the likelihood of progressive collapse of buildings in the event of anomalous loadings. This includes outlining of acceptable risk approach to progressive collapse along with definitions of threads, events control, risk mitigation and practical recommendations for enhancing foundations resistance to progressive collapse.

This research, deals with the linear elastic behavior of curved thin beams resting on Winkler foundation with both compressional and tangential resistances. Thin beam theory is extended to include the effect of curvature and externally distributed moments under static conditions. The computer program (CBFFD) coded in fortran_77 is developed to analyze curved thin beams on Winkler foundation by Fourier series and finite difference methods. The results from these methods are plotted with other solutions to compare and check the accuracy of the used methods.

Experimental modal analysis is an effective, nondestructive method to extract several important physical characteristics of a structural system, such as the mode shapes (deflected form), the natural frequencies of the modes that are excited, and an approximation for the component stiffness. Through past experiences, the authors have identified that the ambient environmental factors, such as temperature and humidity, have an effect on obtained natural frequencies. This finding of the authors agrees with findings published elsewhere. In order to further investigate the issue and quantitatively determine the effect of these factors on modal behavior, this study applies experimental modal analysis on a model timbrel vault. The model dome is constructed at the Peter Kiewit Institute-Structures Laboratory at the University of Nebraska, and stored outside where it is subject to fluctuations in ambient environmental conditions. Experimental modal analysis is performed over a four-month period on the model, and the ambient temperature and relative humidity are recorded. A database is created that includes temperature, relative humidity, measured mode shapes, and natural frequencies. The effects of temperature and humidity on the mode shapes are considered individually and collectively, and correction factors are presented.

All structural systems are not treated equal when response to earthquake-induced forces is of concern. Aspects of structural configuration, symmetry, mass distribution, and vertical regularity must be considered. The importance of strength, stiffness, and ductility in relation to acceptable response must also be appreciated. While considering the lateral force resisting systems we come up with so many options to have structural systems like Bearing wall systems, Moment Resisting frames, Lateral Bracing systems, designing the moment resisting concrete frame structures we have option to use IMRF, OMRF or SMRF. The basic step in conceptual design is to find the best suitable framing system and than lateral load resisting mechanism, while designing structures in the field mostly engineers face problem about the decision of Response Modification Factor R which is a measure of ductility and over strength of the structures. It is used to find the base shear which is distributed on different stories. SMRF and IMRF being emphasized in the research and a detailed computer simulation of the different RCC structures in zone 2 B with different R values i.e., 5.5 and 8.5 given in UBC-1997 are used. Total 04 Structures with different heights of stories, Plans and No. of stories are modeled in software which uses the advanced finite element method to analyze the structure. The conclusions are drawn from the research for the approximation of the most suitable R values and to check the reliability of the values given in UBC.

Over the last few years, slender, clear-span monumental stairs have become increasingly popular in hotels, hospitals, and a variety of other structures. These stairs are vulnerable to annoying vibrations due to walking. Finite element modeling techniques may be used to predict the vibration response of a stair, but experimental verification of these procedures is not available. An experimental and analytical study was performed toward the goal of better understanding vibration characteristics of monumental stairs and to judge the accuracy of finite element modeling predictions. A monumental stair containing heavy glass treads and guardrails, supported by slender hollow structural section (HSS) stringers was used in the study. Experimental modal analysis techniques were used to estimate the stair's modal properties. Stair ascents and descents were also performed to determine the acceleration response. Finite element modeling techniques were used to predict the natural frequencies, accelerance FRF peak magnitudes, and acceleration response to walking. The experimental results are compared to the finite element modeling predictions to determine whether or not the finite element modeling techniques provided reasonably accurate predictions.

Reinforced concrete slabs are among the most common structural elements. In spite of the large number of slabs designed and built, the effect of their details on their behavior under impact loads are not always appreciated or properly taken into account. Reinforced concrete slabs exhibit interesting behavior under severe dynamic loads associated with impact and explosions. The assessment of the behavior of structural concrete slabs subjected to impact loading requires tools that can be used to analyze and design structural element that will improve the state of the art of protective design. The behavior of concrete slabs under impact loading was studied numerically. This numerical study was aimed at understanding the dynamic behavior of structural concrete slabs under impact loading before conducting full scale experimental tests. This study investigated the effects of different types of slab reinforcements and the applied impact loads on the dynamic response and behavior of reinforced concrete slabs. Three-dimensional numerical simulations were performed with the computer code ABAQUS/Explicit, addressing the parameters associated with the impact load and concrete slab. The effects of different types of slab reinforcement and the applied impact load on the behavior and dynamic response of concrete slabs were numerically investigated. Three different types of 90 x 1,524 x 3,353 mm (3–1/2" x 5' x 11') slabs were simulated, as follows: First; using two 152 x 152 mm (6" x 6") meshes of welded steel wires located under 25 mm (1") of concrete cover on both faces of the slab; second, with one 152 x 152 mm (6" x 6") mesh of No. 3 steel bars located at the middle of the slab thickness; and third, with two 152 x 152 mm (6" x 6") meshes of No. 3 steel bars located under 25 mm (1") of concrete cover on both faces of the slab. The drop heights of the impact weight were 152 mm, 305 mm, and 610 mm (6", 12", and 24"), respectively.

Floor vibration serviceability is a primary design consideration for steel framed composite floors. The accuracy of any floor vibration evaluation procedure depends on a reasonably accurate prediction of modal properties. To consider multiple modes, a procedure must also accurately predict the spacing of modal frequencies. The goal of this paper is to investigate the ability of current finite element modeling techniques to accurately predict these modal properties. A composite floor slab was vibration tested to determine its natural frequencies, mode shapes, and accelerance frequency response functions. Analytical predictions were made using a commercially available finite element modeling program. The measured and predicted properties are compared to assess the accuracy of the modeling techniques.

The use of lightweight and high strength materials in building construction have resulted in larger bays and longer spans in floor systems. Lighter materials in addition to the trend towards a "paperless" office decreases damping and the amount of live load on the floors. As a result, floors have become more vulnerable to annoying vibrations induced by human occupancy. The number of complaints by occupants has increased in recent years and floor vibrations have become an area of serviceability concern. Activities like walking, dancing, running, jumping, aerobics, etc. generate floor vibrations and humans have different tolerance levels for these vibrations. Because humans are both the source and the sensor, human-induced vibration can not be isolated from the structure; vibration must be controlled by the floor system. Extensive research has been conducted on human perceptibility of floor vibrations and dynamic behavior of floor systems. The procedures in the AISC/CISC Design Guide 11- Floor Vibrations Due to Human Activity are available for designers to determine acceptable acceleration levels and minimize excessive floor vibrations. The best approach is to design floors that do not allow annoying vibrations, as remedies for floors susceptible to excessive floor vibrations are very expensive. Possible modifications of existing problem floors include adding mass, increasing damping (using partitions, damping posts or tuned mass dampers) and increasing structural stiffness of the floor systems. Open web steel joists are very popular in steel building construction. The open web allows the duct work to be run through the web and maintenance can be done easily after the construction is completed. This makes open web steel joists very feasible and economical; however, vibrations of joist supported floor systems, and in particular, the effect of extended bottom chords, are still not very well understood. Extending joist bottom chords in an attempt to improve problem floors has been reported but without success. However, these retrofits were done after fit-out of the buildings and without introducing a preload into the extensions. The purpose of this study is to examine the effect of bottom chord extensions on deflections and vibration characteristics of joist supported floor systems when joist bottom chord extensions are installed (a) before the concrete was placed, (b) after the fit-out with jacking for a single span footbridge, and (c) after the fit-out without jacking for a three span footbridge. Extensive analytical and experimental studies are performed on two laboratory footbridges with different bottom chord extension configurations to understand the effect of extended bottom chords on deflection, natural frequency, damping, mode shape and effective mass. Finite element computer models are created to simulate and compare the results of stiffness and vibration tests.

The majority of the world's architectural heritage encompasses unreinforced masonry structures, which are generally strong enough for the gravity loads, but are vulnerable against unexpected magnitudes of external out-of-plane loads and environmental effects. The recent trend of rehabilitating and strengthening unreinforced masonry with fiber reinforced polymer laminates, while effective, is not desirable in scenarios where aesthetics are important. Thus, there is a need for an equally effective yet aesthetically pleasing methodology. In this paper, the use of fiber-reinforced-mortars (FRMs) is proposed for masonry rehabilitation and reconstruction applications. Two types of fibers are considered; polyvinyl alcohol (PVA) fibers and novel organic fibers, such as corn silks. Several specimens with different type, size and volume fraction of fibers are tested in compression and flexure. Mixture proportions and the tested mechanical properties of each mixture are gathered in the form of a database. While the study is ongoing and the results are preliminary, it is found that certain volume fractions of PVA fibers are very effective in improving the toughness, ductility and durability of mortars. It is also found that corn silk FRMs show great potential for inexpensive and sustainable means to strengthen masonry structures.

A roofing system (RS) consists of a waterproof membrane, mechanical attachments, cover board (if present), insulation, and vapor or air barrier (retarder — if present). A roof assembly (RA) is defined as an RS that includes a structural deck. Wind uplift ratings are obtained by subjecting RA mockups to dynamic wind loading. Mechanically Attached Roofing Systems (MARS) are one particular type of roof assemblies in which the membrane is attached to the structural deck using mechanical fasteners. The strength of the fastener-deck interface is an important aspect in the successful design of the wind uplift resistance of mechanically attached roof systems. To quantify the fastener-deck interface influence on the wind uplift performance of MARS, seven different roofing assemblies were constructed and tested under dynamic conditions. The experimental investigation identified three parameters namely deck grade, deck gauge and fastener type that have influence on the wind uplift resistance of MARS. Based on this component characterization, fastener pullout resistance (FPR) is identified as a verification factor for system wind resistance estimation.

Adhesive Applied Roofing Systems (AARS) are compact roof systems that use cold adhesives to integrate their components. Differences in adhesive types and method of applications can influence the wind uplift performances of AARS. Full scale experimental studies have been conducted and it revealed that majority of failures occurred at the insulation level and its interface. Based on this observation, a simplified three-dimensional finite element (3D-FE) model is developed to assess the uplift resistance of AARS. However, at this stage, the modeling simulation does not incorporate the studies due to the independency effects (e.g. # of meshes, # of elements and type). The model is assumed as isotropic elastic materials consisting of three parts (insulation, adhesive and insulation). To benchmark the model, new testing specimens were fabricated and tested. The results showed good agreement in comparison with the model. Using the benchmarked model, the effects of the adhesive thickness and its methods of application were investigated. Overall stresses distributions were computed at each level of the models as an indicator of AARS performances. This paper presents the results from this ongoing numerical study.

Diagrid structures have been prevalently used for tall buildings worldwide due to their structural efficiency and aesthetic potential. This paper provides design guidelines for diagrid structures for tall buildings. Optimal grid geometry is discussed for diagrids of various configurations. A stiffness-based design methodology for determining preliminary member sizes for the diagonals is presented. Guidelines are presented for determination of optimal bending and shear deformations depending on grid geometries and height-to-width aspect ratios of diagrid structures.

This paper is an overview of the report "State-of-the-Art Report for Glass Structures" written to fulfill the requirements of Independent Study in Civil Engineering CIEN E9101, Columbia University. The report was done under the guidance of Professor Christian Meyer. The objective was to survey the current trends in the innovative uses of structural glass or glass structures. Most recent printed material was researched in the topic to understand material glass and details, components, and systems for glass structures. Many of the most innovative and contemporary structures built with glass were examined. The current codes and engineering standards offering guidance in the design of glass structures were summarized. Design philosophies, stress and deflection criteria were discussed. Finally, future trends were investigated, and areas of pending and possible new research were outlined. This report was not intended to be a design guide.

The project encountered is a remodeling of a historic building with major structural improvements. The design is intended to preserve the outer appearance of the building and to re-build modern offices inside. This paper presents comparisons of floor layouts, structural connections, and major considerations for practical structural engineers. The project is located in Las Animas County in the City of Trinidad in Colorado. The building used to be the Las Animas County jail. The building is a historic building. It was built about one hundred years ago. The building was designed in the Victorian-style of the 19^th century. It is four stories tall with basement. Today, it is a vacated building of the county. The county now intends to utilize this building as an office building. The The City of Trinidad is considered one of historic sites in Colorado. This building is surrounded by urban buildings with the County Courthouse nearby. A corridor connects the jail to the Las Animas County Courthouse. To preserve this historic building, the county requests that the exterior wall of the building should be kept and its interior structure will be remodeled so that it can be utilized as a modern office building. The county specifications require using IBC 2003 (International Building Code 2003) [1] to process the design. According to IBC2003, this building is in the Seismic Category B zone. Seismic design will be taken into consideration.

In 2005, a $2M gift to the University of Illinois at Chicago by Sid Port in memory of his daughter provided the starting point for the first whole building renovation of one of the original Walter Netsch designed buildings on the UIC campus. Constructed in 1965, Grant Hall was representative of the "Brutalist" architectural style which is the defining theme throughout the master planned campus designed by Netsch. With the building envelope deteriorating and the opportunity to invest in a significant renovation, UIC leadership and architectural consultants proposed a new, modern, energy efficient design for the building which would serve the campus through the middle of the 21^st century while blending in with and paying tribute to the original architecture. Now serving as the Sandi Port Errant Language and Culture Learning Center, the $5.5M project includes a geothermal well field and heat pumps as well as numerous other energy saving features. This paper will discuss the planning and challenges associated with the renovation as well as the considerable debate around such a radical departure from the original design.

Weather conditions have a great effect on building construction projects. The projects would avoid the risks from weather conditions if the weather information were used. This paper proposes to use weather information to support to manage more effectively building construction works on a construction field. A project management software is used to show how the real-time weather information is integrated to schedule management by coding in VBA. Further studies are necessary to complete the supporting system for the utilization of historical weather data and the prediction of weather effects on construction schedules.

The competitive environment in the construction industry has been causing contractors to bid with a very small margin of profit. At the same time, overhead costs are ever increasing relative to the project direct costs, as a result of increased requirements for trades coordination, works supervision, and the provision of temporary site facilities. This paper examines the components of the project overhead costs through a thorough study of actual cost data from building-type projects undertaken by a major contracting firm. To this end, the paper makes a comprehensive classification of such costs and presents statistics that can be useful in assisting cost professionals in both estimating and controlling this project's crucial cost component. Finally, the paper discusses three sub-processes aimed at (1) maintaining an updated database of previously incurred overhead costs, (2) estimating the overhead costs for new projects, and (3) controlling the same throughout the construction period.

It is long recognized by the industry practitioners that how well preproject planning is conducted has great impact on project outcome. Through industry project data collection and model analysis, this research intends to investigate the relationship between preproject planning and project success. In early stage of the project life cycle, essential project information is collected and crucial decisions are made. It is also at this stage where risks associated with the project are analyzed and the specific project execution approach is defined. To assist with the early planning process, Construction Industry Institute (CII) has developed a scope definition tool, Project Definition Rating Index (PDRI) for industrial and building industry. Since its introduction, PDRI has been widely used by the industry and researchers have been using the PDRI to collect preproject planning information from the industry. Scope definition information as well as project performance are collected and used for this research analysis. This research summarizes preproject planning data collected from 62 industrial projects and 78 building projects, representing approximately $5 billion in total construction cost. Based on the information obtained, preproject planning was identified as having direct impact on the project success (cost and schedule performance). Two techniques were then used to develop models for predicting cost and schedule growth: statistical analysis, and artificial neural networks (ANN). The research results provide a valuable source of information for the industry practitioners that proves better planning in the early stage of the project life cycle have positive impact on the final project outcome.

Delays are the most common and also the most costly problem on construction projects. If the construction time period is extended, higher borrowing costs, inflation and other commercial factors will increase the construction costs. And if the construction costs increase, from an economic perspective, the project may lack an acceptable and functional performance. Thus, the primary objective during the construction process is to complete the project on time and within budget, while meeting established quality requirements and other specifications. However, in some cases, delays during construction can create huge cost damages, and these damages can result in the projects' parties taking legal action against each other through a construction claim. Historically, scheduling and finding the delays in big construction and commercial construction projects was based on discussion within an engineering department involved in the planning sector of the construction business. The reason for delay discussion is all about the effect of delays on the cost of construction. The amount of money involved in big construction is huge. And by extending the construction time, other expenses would be added to the original construction cost such as inflation, the cost of material and the interest costs of the investor's money. With smaller construction projects like housing, given that the amount of money involved was small, few investors were serious about the postponement of the completion time of the project. But today, the construction cost of a brand new high end house is more than in the past. In some places in the Toronto area, the cost of construction and land cost together become more than a few million dollars. This kind of cost causes investors to be far more interested in hiring a project scheduler to control the builder's time firmly in order to avoid the negative effects of the inflation cost of material and higher borrowing costs of the investor's money. Usually, the claims for residential projects are premised on two concepts: firstly, the costs of the late practice of a project, which is usually determined at the same rate as inflation; and secondly, the profit acquired from the investment, which is counted as interest on the of amount of money stock in the project for the duration of time (delay) that the project is not ready for use. The costs resulting from delays represent a percentage of the overall contract value, so, the cost of delay would be much greater in larger projects.

Information processing is critical to the successful development and execution of a construction project plan. Currently, Building Information Modeling (BIM) has been widely used in representing the physical and functional characteristics of design and construction. However, in order to use BIM effectively in construction project planning, more construction knowledge should be transformed and integrated. This paper proposes an activity-based modeling approach to process project information in an organized manner and proposes a Multi-Dimensional (MD) CAD model. The MD CAD model is composed of the MD CAD objects. The model can assist project planners in assessing information concerning the inter-relationships between schedule, cost, resources, and work areas. A computer implementation called MD-Construction Project Management Information System (MD-CPMIS) is presented to verify the feasibility of the proposed approach.

The reliability and accuracy of ‘preliminary estimate' and ‘preliminary schedule' as part of front-end planning is mainly affected by the ‘specific characteristics of a construction project', ‘project details determined at the time of planning', ‘experience of the planners', and ‘historical database of similar projects'. The purpose of this paper is to evaluate the variables that critically influence the viability of automated front-end planning tools. A framework of variables is first proposed in order to evaluate the comprehensiveness of the system objectives. Because there have not been many efforts to develop this type of tools, this study introduces recent real-world cases of the automated front-end planning system. Finally, findings from the entire research process are briefly summarized, and implications and lessons learned for further development are outlined as well.

A potential facility project management involving time used of a project can always be tradeoff by additional resources input. Such a tradeoff may come from different options of the activity on the critical path of the project. Finding the optimal combination of time-cost tradeoffs include the use of critical path method and mathematical programming, which considering large numbers of permutations involved. If a CPM network has m activities, with O₁,, O₂, ..., O_m options respectively, will have O₁ x O₂ x ... x O_m alternatives. Using the hull convex principle to rule out non-active options, the paper develops the piece-wise segmentation concept into a more efficient algorithm. By which the linear programming model divide an activity into piece-wise segments to approach the time-cost trade-off problem. Also, using the problem structure of the time-cost trade-offs, such a k-piece-wise approach can simplify the presentation of linear programming problem, which can be used easily but efficiency in spreadsheet. An illustrative example of such algorithm was presented, and the step by step simulation processes were showed. How the optimal project time-cost solutions were attained via different combinations of reducing time in multi-option activity was showed.

Coastal areas in Egypt and all over the world suffer from the excess stress of human activities specially the touristic development of the coastal waterfront and the urban extension which negatively affect the environment. Recently there has been an increase in the understanding of the coastal areas problems in Egypt and there have been effective decisions and moves towards the protection of the environment in general and the coastal one in particular, since it is considered to be a national heritage which must be kept well and preserved. This research is a positive step in the resent trend of the environmental urban development of the coastal areas in Egypt. Here we will discuss, in brief, the main principles and considerations which were announced, in March 1996, by the environment affairs authority with regard to the protection of the water front shore. This regulations and considerations are applied in all coastal regions in Egypt either by the Red sea side or the Mediterranean.

With increased energy costs, driven by a higher demand and dwindling supplies, the search for alternative and renewable energies to compensate or even replace the current energy production technology is very necessary. A properly sized and installed solar energy collection system can be a practical alternative for acquiring all or some of your energy needs. The main goal of this research was to conduct an experimental analysis of an integrated photovoltaic and thermal system. The design and development was initialized by a group of students and advisors from both the University of Missouri-Rolla and Crowder College with the intent to use the hybrid system as part of the solar houses in the upcoming solar decathlons. Previous research studies on hybrid roof systems have shown increased performance however the differences in the systems studied vary in their setups and use of materials. In the case of this study a series of copper tubes were integrated into a metal seam roof with an amorphous silicon panel encased in low iron glass. This experiment encompassed almost 160 square feet of hybrid Solar Thermal Electric Panel (STEP) system panels and performance data acquired was used for input to computer simulation software to optimize the system for application to the UMR/RTI solar house that is entered into the 2005 DoE's Solar Decathlon. Based on experimental tests overall efficiency of the STEP system is 50% while a separate thermal and electric system is estimated to be 26% for the same roof area. An assumption for the thermal systems is that they are of similar makeup and their efficiency is based on an ambient input temperature. The glazed versus unglazed analysis yielded a glazed panel reducing the PV collection by 23% and increasing the thermal collection by 200%. In conclusion this paper will discuss additional performance based analysis on the STEP system thermal and electric outcomes.

In response to several failed facility maintenance contracts, Air Force Space Command initiated a Tiger Team aimed at improving the basic contract structure. The Tiger Team reviewed all out sourced Civil Engineering squadrons in the command, determining that the relationship between professional engineering and architectural services, the vendor, and the client (USAF) had a strong connection to how the contract was perceived. Typically, Air Force bases were strongly satisfied when they either had in-house engineering services or maintained a traditional agent relationship with an architectural /engineering firm. In contrast, the relationships were typically hostile in those contracts where the Air Force severed the traditional agent relationship by allowing the vendor to provide all or most engineering services. This paper will discuss the agent role of architects and engineer services, the Federal Acquisition Rules which apply, the impact of not maintaining these relationships, and, finally, how AFSPC restructured on Air Force Base's maintenance contract to reflect the traditional professional services relationships.

This paper presents a literature search on the early developments in floor and roof slabs constructed of "assembled concrete blocks" made from precast, lightweight hollow core blocks, commonly referred to today as Dox Plank. This survey includes period design guides, reference standards, United States patents, technical manuals, product catalogs, plank manufacturers, design assumptions, design theory, and the manufacture of planks. The findings will aid the architect/engineer in conducting a performance evaluation by identifying the original design parameters, such as the allowable unit stresses, area of embedded steel, material properties, etc., as well as by identifying serviceability concerns. Assembled concrete block type planks are formed by assembling a row of hollow core, lightweight concrete blocks into a prestressed plank. The most common of the assembled concrete block systems was the "Dox Plank," initially known as "Doc's Blocks." It was named for its inventor Bernhard A. "Doc" Vander Heyden, who patented improvements in the planks and the methods of constructing them in 1954 (United States Patent No. 2,696,729), and subsequent improvements in 1965 (United States Patent No. 3,172,932). Although Dox Plank is just one variation on the assembled concrete block system, it came to represent the industry.

As trained architects and engineers, we are privileged to have access to building performance failures of all types on a daily basis. Certainly, the presence and infiltration of water, in any of its many forms — such as moisture, precipitation, vapor, and humidity — are responsible for the vast majority of building performance failures. During the course of our presentation, we will use a building system failure that showcases many common deficiencies that cause damage. This case study concerns an Exterior Insulation and Finish System (EIFS) but the problems also occur in many other types of envelope systems.

Whether you are selecting windows for a residential house or for a large commercial project, you need to know a few things before you make your selection. Do you know what you are really getting with a window having a particular performance rating? What does the performance rating mean? What procedures and practices can a designer, or owner, implement to reduce their risk? We will attempt to answer these and other concerns related to selecting windows regarding water penetration, with limited discussion related to structural performance and air infiltration. We will not attempt to address selection of windows having an adequate performance rating for a particular area. Selection of a performance rating for windows should be based on typical weather for a region and building code requirements. For the laymen owner, have the window manufacturer explain, convince, and prove to you that a certain performance rating is adequate for the location of your project. Current industry standards provide methods and guidelines for testing of windows in the laboratory for certification. Industry standards also provide methods and guidelines for testing of windows in the field that reduce testing pressures; however, designers do not have to adhere to these standards and can specify more stringent requirements as part of the project specifications.

Multi-hazard consideration is gaining importance within the design and retrofit process of many important structures. The primary benefits for multi-hazard approaches to the structural engineer include: (1) identification of the mitigation alternatives that address either single or multiple hazards, and (2) optimization of these hazard mitigation strategies. However, this recent popularity of a unified multi-hazard approach for design or retrofit of structures could be attributed to the high cost of the required mitigation strategies compared to retrofit of the structure for a single hazard and the limited information on life-cycle cost. Thus, a conceptual framework is required for rational comparison of hazard mitigation strategies for structures experiencing multiple environmental hazards, incorporating life-cycle cost assessment. This paper presents a computational methodology for the optimal life-cycle cost of seismic and wind-excited structures retrofitted with passive energy dissipation devices such as metallic yielding dampers, viscous fluid dampers, and viscoelastic solid dampers. In addition to designing in agreement with the relevant codes of practice, it is important in design or retrofit of structures to consider that the performance of passive energy dissipation devices for reducing the structural responses depends on the distribution, type, size, and number of dampers in the structure. The proposed computational framework integrates a genetic algorithm (GA) based methodology to address these optimization issues of multi-hazard design within the context of nonlinear steel frame structures. Optimization objectives in this framework include minimizing both the damage to and life-cycle cost of a structure, which is vulnerable to one or two of the main natural hazards: earthquakes and strong wind loads. While considering the essential conflicts in dynamic response demands of the structures to these two natural phenomena, passively damped structural designs evolve toward configurations that satisfy prescribed constraints. Monte Carlo simulation models are generated to evaluate various retrofit strategies with different damage levels possible over the life-cycle. The life-cycle cost associated with each scenario is computed, with a discount factor, to obtain the optimum life-cycle cost for various retrofit strategies. The specifics of the computational framework are illustrated through example case studies to highlight the potential benefits of the proposed computational multi-hazard design approach.

Changing environmental interests in the wire and cable industry (WCI) have generated studies into the eco-performance of various data and communication cabling system alternatives for computers and local area networks (LAN). To accurately assess the various alternatives, the installed electronic functionality and fire safety performance requirements of the various end-use product options must be equivalent. In buildings, high fire performance (HFP) based polyvinyl chloride (PVC) sheathed and perfluoropolymer (PFP) insulated (CMP or PVC/PFP) cables can be routed directly in concealed plenum spaces without the use of additional metal conduit fire protection. Products that do not meet specific high fire-performance criteria, such as low-smoke zero-halogen (LSZH/PE) cables or riser-rated cables (CMR or PVC/PE), often must be protected inside other structures, typically metal EMT conduit or trunking. Life cycle analysis (LCA) via ISO 14040 methodology is used to evaluate cabling alternatives using an appropriate functional unit. Copper wire is identified as a significant contributor to all impact categories, and the major contributor for human toxicity. The burdens for steel conduits dominate all other impact categories studied for systems requiring steel for fire performance code compliance. The additional fire safety and installation advantages provided by the CMP cables offset the environmental burdens associated with the initial manufacture of just the cable. Thus, CMP cables provide superior overall fire safety, environmental performance, and economic benefits versus LSZH/PE and CMR cables installed in metal conduits for U.S. plenum cable installations. During the writing of this paper, new fire safety research became available indicating that EMT die cast conduit-couplings can begin to weaken, melt and fail to fire-protect in less than 4 minutes at or less than 400°C (images to be shown). This finding is not consistent with previous beliefs that the fire performance of CMR or LSZH cable in EMT conduit was equal to the performance of CMP cable.

Facility damage assessments are performed in the hours and days following a disaster event, and the individuals who conduct these assessments are often volunteers from the impacted community. Consequently, these volunteers typically have limited knowledge of facilities, which may cause biased and inaccurate damage judgments. To overcome these important limitations in skills and knowledge, a study was initiated as part of a collaborative effort between the civil engineering and psychology communities. This study investigated the damage assessment process using a virtual computer-based environment. Different types of damage were simulated on three-dimensional models of buildings, and participants were asked to view the damaged facilities in order to develop a description of the damage and an estimate of the quantity and magnitude of the destruction. Following their assessments, participants were asked a series of questions to ascertain how they arrived at their judgments. The data analysis revealed that engineers nearly always classified the severity of the damage correctly and relied on their technical and conceptual knowledge of engineering to form their judgments. In contrast, non-engineers nearly always incorrectly classified the severity of damage and relied on mental anchors, heuristics, and non-technical knowledge to form their judgments.

Throughout recent years, to minimize the cost of construction, a large number of multipurpose spaces have been built using lightweight, less expensive materials without considering or designing for noise control to mitigate any sound that is loud, unpleasant, unexpected, or undesired yet after construction is completed, noise issues are often evident within the space and, if severe enough, may render the intended function of the structure useless. To address this problem, this paper is intended to summarize some of the common solutions to resolve noise issues in multipurpose rooms. The report focuses on solutions for existing projects primarily, but it is also sensitive to budget constraints and the impact of renovation. Typical multipurpose rooms researched have a volume of 50,000–150,000 cubic feet and are expected to be used for speech activities, small music functions, and some physical sports activities. Therefore, this paper will introduce some fundamentals of room acoustics including interior surface materials and construction. Also included are typical noise issues from interior sources, solutions that can be taken within the building to attenuate noise, and the trade-offs associated with each solution.

The prediction of sound levels in rooms is usually accomplished in one of two ways: using simple diffuse field theory or full computer modeling using an acoustic CAD program. The simple diffuse field theory can be easily calculated by hand or on a spreadsheet but is limited in its accuracy. Acoustic CAD programs, usually based on ray tracing, beam tracing, or image methods, can be far more accurate, but require expensive and proprietary software and generating the computer models for use by the software can be time consuming. A method of sound level prediction with more accuracy than simple diffuse theory but that can still be implemented by hand or by spreadsheet would be very beneficial to consultants and engineers. In this paper, we present a simplified approximation to diffuse steady state radiosity for the prediction of sound pressure levels in six sided rectangular rooms. The steady state diffuse radiosity method is reduced to a six surface problem and a closed form solution for computing the approximate power on the entire enclosure surface is presented. Closed form expressions for the form factors between all surfaces and configuration factors to and from all surfaces are also presented. The simplified method is used to predict sound levels in an empty classroom.

In this article, building air conditioning using wind as a natural factor, utilizing Iranian Traditional. Architecture aimed at a reduction in energy use is discussed. One way to achieve this is using Baadgirs (wind catchers). In wind catchers, the clean and sustained wind energy is used such that wind enters the wind catcher and then into the residential space. If by using secondary means such as water one could wet and cool the wind, a more desired air would enter the building. This article purports to introduce two new types of wind catchers in an up-to-date form, to be used in modern buildings.

Design of concrete mixtures is the process of selecting the most economical and practical proportions of all the ingredients to produce quality concrete. Because of the nature of the mix design process and all the heuristic knowledge that is associated with it, concrete mix design lends itself well to a knowledge-based application. This paper describes a prototype knowledge-based system called HPCMIX that can be used to load the experimental data, develop several statistical models to determine the responses, evaluate the predicted models, and predict the 28 days strength and slump. It can also be used to design HPC mix proportions that are subjected to specified constraints (e.g. strength and slump). It is capable of selecting proportions of mixing water, cement, supplementary cementitious materials, aggregates and superplasticizer, with consideration being given to the effects of air content as well as water contributed by superplasticizer and moisture conditions of aggregates. As most of knowledge-based systems, this system has explanation facilities, can be incrementally expanded, and has an easy to understand knowledge base. The system was tested on a sample project. The system's selection of the concrete proportions compared favourably with the expert's selection. The system is very useful for civil engineering students as well as practicing engineers.

This paper describes a software program developed to control smart building components (SBCs) and improve comfort in buildings that use SBCs. In a virtual environment, this software package allows to control automatically the performance of buildings that include SBCs in their envelope and systems. The software has been calibrated on a simple model of a virtual building that is characterized by an SB intelligent skin, so that it is enabled to change its own characteristics and to modulate them in accordance to variability of boundary conditions. Internal comfort is guaranteed by hourly check and automatic management of the following elements: (a) Electrochromic glasses, (b) External vertical screening, (c) Internal vertical screening, (d) Ventilation grids, and (e) Radiant floor heating system.

The importance of energy efficient buildings has assumed great urgency in light of fast depleting energy resources, energy scarcity and increasing environmental pollution. Innovative ways to cut down energy consumption are necessary. The construction industry is one of the largest energy consuming sectors. In modern buildings significant amount of energy is consumed to keep the building environment comfortable. In developing countries like India, rising population, increasing standards of living and rapid urbanization result in an increase in building construction activities. To achieve the collective objectives of energy security and environmental protection, eco-sensitive buildings that utilize their resources judiciously, minimize their emissions and have efficient waste management systems, should be considered and designed. The available options in architectural intervention, building materials and design methodologies need to be carefully evaluated to minimize energy usage, minimize the ecological degradation that may be caused by the construction of the building and provide cost effective solutions. The aim is to achieve the desired comfort with the least input of conventional energy. Architects and designers accomplish the task through solar passive design, use of renewable energy technology systems, and/or natural building materials. While designing such buildings, not only new building stock can be targeted but also existing buildings can be retrofitted with energy efficient and eco-friendly technologies, thereby substantially reducing energy consumption. All put together is Energy Efficient Housing.

The owners' commitment level to the completion of the sustainable project is imperative for implementing sustainability in the Architecture, Engineering, and Construction industry. Besides the owners, the architects, engineers, and contractors also play a great role in the construction process. It was hypothesized in this paper that the architects, engineers, and contractors believe that the quality of the completed structure is essential for maintaining owners' level of commitment to sustainability. This paper presents the results for the survey on evaluating the successful sustainable outcome criteria so that practical experiences from their point of view on sustainability are obtained. Respondents were asked to answer which attribute has greater influence on the attribute one level higher in the hierarchy and to what extent they prefer. Twenty completed surveys were collected and the analytic hierarchy process (AHP) was applied to analyze the data. The results indicate that the quality of the finished product is the most significant effect on sustainability because the overall performance after completion is the most important factor when designing and building a facility.

Healthcare is one of the most significant built environment markets today with over 120,000 buildings in the United States. Moreover, in the next 15 years, an estimated $300 billion will be spent on hospital construction across the United States; therefore, there is a great opportunity for research and improvements to be made in this area. The built environment has a great impact on healthcare, particularly on the health, safety and well-being of patients and staff. Green healthcare offers benefit of improved clinical outcomes, reducing operating costs, energy consumption and water use. Children's hospitals are the most specialized centers for care, providing care for children with complex and rare conditions and they are therefore amongst the most complex types of facilities to design, construct and operate. This paper outlines the findings from three children's hospitals with different levels of sustainability in regards to the project delivery process, greening strategies and lean principles. This paper will provide a thorough understanding of the building delivery process in green children's hospitals, starting from programming, through design, construction, operations and maintenance. Using the Dell Children's Hospital of Austin, the Children's Hospital of Pittsburgh and the Hershey Medical Center Children's Hospital, this paper will show how coupling lean and green can make healthcare facilities not only efficient, but healthful places for treatment.

This paper presents the results of a pilot study at Penn State University to compare the structural behavior of three types of masonry that have some sustainable attributes. The three masonry types chosen consisted of concrete masonry unit (CMU), autoclaved aerated concrete (AAC), and adobe. Design professionals are interested in the relative performance of sustainable wall systems and this pilot study was motivated because of the lack of such a comparative study. In the study reported in this paper, 4 ft x 4 ft wall specimens were tested in shear and flexure under dry and wet conditions. A specially made spray rack was used to simulate rain condition on wall specimens before structural tests for wet condition. Comparison of the test results and observations made during the tests are discussed.

Construction site layouts involve identifying the positions of temporary facilities on site, and play a major role in the safety and productivity of operations, particularly when site space is restricted. This paper presents a new method of safety assessment of construction site using geographic information system (GIS). First, safety issues on construction sites are discussed and the factors that contribute to unsafe sites are outlined. A procedure for dynamic safety assessment of site layout has been developed in a GIS to obtain proper safety zones around the construction temporary facilities. Safety-related temporary facilities and potential places for locating temporary facilities were established. Furthermore, optimum placement of temporary facilities on the site was considered. An application example is analyzed to demonstrate the application of the model in assessment of construction site layouts based on safety consideration. This shows the capability of GIS combination for proper site layout which can lead to significant improvement in the safety and cost performance construction projects.

Increasing complexity of our codes and standards as we delve deeper in the information era makes conforming accurately to the specifications a cumbersome process. The concept of intelligent digital design within the context of structural engineering in the 21^st. century will provide key solutions in simplifying the engineering design process. The intelligent structural design described in this work focuses on the relationship among the Information Management Systems in general and Masonry Information Management System (MIMS) in particular along with the Building Information Modeling (BIM). By providing more accurate information and interactive structural elements, intelligent design offers engineers and consultants efficient and unambiguous methods to validate design assumptions against specifications and alternatives in a digital environment to achieve design objectives.

The challenge in understanding immense aspects of architectural design process has been the central issue in an attempt to computationally define design process and design knowledge. Relationships between designs and the sources of the ideas used to generate them are extremely complicated to quantify, and to represent in the manner of explicit knowledge and data. Parameters that influence architectural design include a body of knowledge about the subject-matter, requirements of all involved parties, information about prevailing conditions on the site, and information about the traits and trends in the society served by the building. This paper discusses development of knowledge-based representations of architectural design process, particularly focusing on representations of design knowledge and factors in ontological framework. A case study for tall building design is used to demonstrate the representations. Web-based application is presented to exhibit the method for utilization in the schematic design, especially for decision-making process.

This paper compares typical architectural comprehensive studios to a design project that I have created in which the traditional design order has been reversed. The traditional process for most academic building design projects is to study a project's macro-scaled issues first and eventually focus in to the building details. Through the macro-to-micro process, the building systems, structure, and assemblages are reactionary to the building design. In this studio's reversed order, students started at the building core, designing their building around an investigation of building systems. Next, students examined building structure, construction methods, assemblages, building organization, and then finally external context. This paper demonstrates that reversing the typical design order results in designs that have a greater conceptual understanding of building systems, assemblages, and materials than traditional design method. Although the paper focuses specifically the design studios within architectural programs, I believe that the concepts of reversing our traditional order of design, designing inside (out), can be transferable to all building design professionals.

Ground Penetrating Radar (GPR) is commonly used for locating abnormalities or as a means of quality control in buildings and infrastructures. The objective of this project is to accurately detect the thickness of concrete pavement sections and to minimize the need for core samples using GPR. The project is sponsored by the Nebraska Department of Roads and several project sites in Nebraska are utilized for case studies. Through the use of the SIR-3000 GPR equipment and a 1500 MHz antenna, several pavement sections are scanned, validation cores are taken, and accuracy is evaluated. Laboratory and field experiments are also utilized to develop practical and inexpensive means to increase the accuracy of the GPR scans and further the confidence in the use of the system by professionals. Through the use of a strong reflection material placed at the bottom of the pavement, the thickness of the pavement may be determined accurately. With fewer core samples and a strong ground reflection at the bottom of the concrete, the GPR data can be calibrated for variances in concrete mixture, water content, and ground conditions. The study is still ongoing; however, the preliminary results show that with the use of inexpensive construction adjustments, such as use of a high reflection metal at the bottom of a concrete section, an accurate thickness measurement can be gathered without as many destructive core samples.