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Building Integration Solutions Proceedings of the 2006 Architectural Engineering National Conference

March 29–April 1, 2006 Omaha, Nebraska, USA

Editor(s): Mohammed Ettouney

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BUILDING ENVELOPE 1

Select this Article		Synthetic Stone Veneer: Why Problems Occur and How to Avoid Them Edward L. Fronapfel, M.S., P.E. and Brian Erickson, E.I.T. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)1 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Stone has been used as a building material since the literal Stone Age and it is not going to be an extinct construction material anytime soon. While natural stone is used in all aspects of home construction such as exterior wall claddings, in the early 1960's companies began manufacturing synthetic or “fake” stones that replicated natural stones. Advancements in technology throughout the years have created more authentic artificial stones that continue to replace natural stones for use as exterior wall claddings. Without being an advocate of the synthetic stone industry, the products they manufacture offer many advantages over natural stone. Lower cost, greater availability, wide variety of colors and styles, lighter weight, quicker installation time, small waste factors due to custom stone pieces such as corners and water tables, and repeatability and reliance for the construction trades installing the products are some advantages to manufactured stone. Regardless of the quality of the product used to skin a building, the quality of any exterior cladding ultimately depends on the quality of installation. This article will attempt to provide the reader with the information needed to ensure their stone veneer and related building components do not suffer failures related to the improper installation and lack of detailing at important locations.

Select this Article		Transparent Shading Device as Daylighting System Svetlana Olbina, Ph.D. and Yvan Beliveau, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)2 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Most shading device systems installed in windows or glass walls are used only for protection from overheating and glare, neglecting other possible functions, such as increasing the daylight level in the space or collecting solar energy. The blinds are usually made of opaque or translucent materials, and if they are partially or completely closed, a direct view to the outside is blocked. A balance between a sufficient amount of daylight and protection from overheating of the space in summer is not often achieved due to inappropriate control of the blinds' tilt angle. This paper explains research that had the purpose to study daylighting performance of a transparent shading device as part of a window system. The objective of the research was to propose a new design of transparent shading device with improved daylighting performance. A new shading device system has the triangular cross section of the blinds. Application of the clear plastic and silver reflective coating as the materials for the new blinds utilizes the principles of optical physics in the design. A case study was performed to analyze daylighting performance of the new transparent shading device system, an existing opaque system, and a patented transparent system. Daylighting performances of the three shading device systems were compared to select the system with the best performance. The paper presents results of daylighting simulation of the three systems installed in the curtain wall at a proposed office building located in Roanoke, Virginia. The output of simulation is actual values of illuminance and luminance in the space obtained by the application of the different shading device systems. Comparison of the daylighting performance for the three shading device systems showed that the new system seemed to provide the highest level of daylight in the space, given the limitations of this study. Being made of transparent material, the new shading device system also provides transparency of the window/curtain wall.

Select this Article		Thermal Behavior of Precast Prestressed Concrete Three‐Wythe Sandwich Wall Panels Byoung‐Jun Lee and Stephen Pessiki ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)3 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Precast concrete sandwich wall panels are often used for building exterior cladding and may also serve as bearing or shear walls. These precast concrete sandwich wall panels are commonly constructed of two wythes of concrete separated by a layer of thermal insulation. In these two‐wythe panels, solid concrete regions which extend directly through the entire thickness of the panel are often provided for embedded hardware for lifting, handling, and connections, or to provide composite action. These solid concrete regions have a significant adverse impact on the thermal performance of the panels. This research was directed towards the development of precast concrete three‐wythe sandwich wall panels with improved thermal and structural performance. A three‐wythe panel has three concrete wythes and two insulation layers. All three concrete wythes are connected by solid concrete regions, and the connections between successive concrete wythes are staggered in location so that no concrete path extends directly through the entire thickness of the panel. This paper describes the thermal performance of precast concrete three‐wythe sandwich wall panels. Possible panel configurations of the three‐wythe panels are proposed, and their thermal performance is studied by estimating R‐values using the finite element method (FEM) analysis. It was found that, in general, the thermal performance of three‐wythe panels is better than that of two‐wythe panels due to the increased thermal path length through the panel.

Select this Article		To Apply Numerical Simulation to Assist Drying Capacity Experiment of Light‐Frame Wall Systems Qinru Li, Paul Fazio, and Jiwu Rao ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)4 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract HAM models represent and solve the underline physical heat‐air‐moisture transfer processing within the building envelope by governing equations and simulation programs. Using the weather data as the boundary conditions, these models have been used to study and predict the moisture performance of the building envelope systems. In this paper, an integrated experimental approach is present to apply a HAM model to the setup and conditions of lab tests and to provide further insight to the experiment setup and interpretation. The testing program investigates the drying capability of wood frame wall assemblies with variations in sheathing, cladding, and vapor barrier. The numerical simulation model handles moisture flow of vapor and liquid phases in 2D using material properties from ASHREA publication; and the lab condition and weather data works as the boundary conditions. From the comparison between simulation and preliminary experimental result, the factors could influence the accuracy of the experiment are detected and analyzed. The improvements are summarized and applied in the following full‐size experiment. In addition, simulations based on parameters slightly different from the test setting are carried out to evaluate the influences of aspect ratio of stud cavity, boundary settings and initial moisture content to the evaporation rate of the water tray.

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BUILDING ENVELOPE 2

Select this Article		Digital Form‐Finding: A Case Study in Complex Geometry M. Elnahas and K. Nassar ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)5 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper aims to investigate recent trends in computationally based design. The case study in this paper illustrates a parametric approach to designing and building complexly shaped architecture. The selected project, designed by the primary author for an international design competition, demonstrates benefits and problems associated with the use of advanced digital design and manufacturing techniques. The development of sophisticated digitally based environments has led directly to a preoccupation with their use in developing forms and shapes involving highly complex geometric forms and manipulations. A common approach here is to define a building envelope in terms of a series of parametrically defined elements such as the structural ribs. A contrasting parametric approach would be to define measures that control the geometric definition of the outside envelope directly and generate the supporting structure subsequently. The latter approach is exemplified in a highly transparent pavilion that is built of doubly curved acrylic skin over hollow‐tube steel ribs. The complex external shape is a priori determined. Sectional planes are passed at regular intervals through the whole shape; and the geometry of the intersection is used to define the shapes of structural members. As a result, orthogonal egg‐crate structural system is formed of planar but curvilinear ribs. Shorter blue ribs are assigned primary structural functions. The pavilion is fitted with aluminum horizontal louvers for solar control.

Select this Article		Development of Failure Prediction Models for Structural Sealant Glazing Systems under Cyclic Racking Displacement Conditions A. M. Memari, X. Chen, P. A. Kremer, and R. A. Behr ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)6 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract A research project was undertaken recently at Penn State University to study the simulated seismic performance of “Structural Sealant Glazing” (SSG) used to adhere glass panels to common curtain wall framing systems. In the most common type of SSG curtain wall construction, referred to as “two‐side” SSG, two glass panel edges (typically opposing vertical edges) are adhered to the support framing using structural sealant, while the other glass panel edges are mechanically fastened to the support framing. In this study, full‐scale two‐side SSG curtain wall mock‐ups consisting of three, side‐by‐side glass panels were subjected to cyclic racking displacements to characterize their performance and to identify sealant and glass component failure modes under serviceability and ultimate racking displacement conditions. Attempts were also made to develop kinematic‐based models to predict failure states (e.g., structural sealant failure) of the SSG curtain walls. This paper discusses the details of the predictive model and its evaluation on the basis of comparisons with mock‐up test data. The model developed appears to give good estimates of the observed sealant failure drift. Conclusions and recommendations regarding appropriateness and limitations of the predictive model are provided.

Select this Article		Feasibility of a Unique Skylight Design for Day and Night Illumination of a Large Volume Room Mark E. Snyder and Ahmed Megri ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)7 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The feasibility of a unique daylighting approach using a skylight with clerestory windows, also known as a roof monitor, and an outdoor lighting array will be evaluated. The design will illuminate a room 100 feet wide, 100 feet long and 75 feet high, equivalent to a large auditorium located at 40 degrees north latitude. Comparisons will be made to flat skylight wells for the same volume. The design will be shown meet lighting requirements that satisfy Illuminating Engineering Society of North America (IESNA) standards for day and night for tasks of low contrast and small size (i.e. criteria F). The design will be tested with AGI32 version 1.7 software created by Lighting Analysts, Inc of Littleton Colorado. Results will show the unique skylight meets IESNA criteria F during the daytime with an assist by external lighting as daylight is reduced by the setting sun.

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COMPOSITE AND INNOVATIVE NEW MATERIALS

Select this Article		The Use of Clay as Pozzolana for Building Purposes in Ghana Afua O. Adu‐Boateng and M. Bediako ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)8 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Construction generally in Ghana has been experiencing difficulties over the years due to rising cost in construction materials. As has been the case in most developing countries, Portland cement has been the main material used in construction and the situation in Ghana is not different. In Ghana, the cost of Portland cement has increased over 500 percent within the last ten years. This phenomenon has by and large increased construction cost in Ghana. This situation has not generally only affected the construction trends in Ghana but has seriously affected the housing situation in Ghana, especially among the poor. In view of this situation, the Universities and the Research Institutions in Ghana have been urged by policy makers to research into other alternative and cheaper methods of construction materials. It is in line with this policy that let the Building and Road Research Institute (BRRI) of Council for Scientific and Industrial Research (CSIR) to research into the use of clay as Pozzolana for building purposes. The paper will seek to discuss the strength development, water absorption, consistencies and setting times of mortar cubes prepared from_cement with 20 to 30 percent replacement by pozzolana calcined at 700 degrees C and 900 degrees C. It will also present the cost in reduction in the use of Clay as Pozzolana for building purposes as against the use of Portland cement. The lessons learnt so far in some pilot projects in Ghana will be elucidated with the view of enriching experiences for improving similar projects elsewhere especially in developing countries.

Select this Article		Creep Induced Deflections of Concrete Elements Reinforced with Polymer Composite Bars F. Aguíñiga, Ph. D. and H. Estrada, Ph. D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)9 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract With the increasing costs of steel reinforcement and corrosion related problems, the construction industry is looking for alternative materials to substitute steel reinforcement. This paper studies the application of composite fiber reinforced polymer bars to reinforce concrete flexural elements. As an example, Glass Fiber Reinforced Polymer (GFRP) composite bars have a modulus of elasticity of approximately 1/6 of the modulus of elasticity of steel reinforcement. This fact makes the design of GFRP‐reinforced concrete elements governed by serviceability requirements, rather than by strength requirements in most cases. In addition to that, polymer composite bars have been shown to creep under sustained loads. Therefore, this paper presents an analytical method that can be used to compute the deflections induced by creep in polymer composite reinforced concrete flexural elements. This method can be a valuable tool for the design of concrete elements reinforced with polymer composite bars where deflections are the governing design factor.

Select this Article		Structural Properties of a New Material Made of Waste Paper B. Fuller, A. Fafitis, and J. Santamaria ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)10 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Papercrete is a new construction material made most often with waste paper, cement and water. People have been using papercrete to build low cost homes without a clear understanding of its structural properties. The purpose of this study is to obtain some mechanical and physical parameters of papercrete by doing several laboratory tests. The samples tested were made following the most common mixes that papercrete makers are using currently. The experimental setup used to test the samples is briefly described and some test results are tabulated in tables. This will allow us to reach some conclusions and make several recommendations for using papercrete to build homes.

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CURTAIN WALLS

Select this Article		AISI Codes, Standards and Design Guides on Cold‐Formed Steel Framing J. W. Larson, P.E., F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)11 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract To enable the increased use of cold‐formed steel framing, the American Iron and Steel Institute (AISI) in its role as an ANSI‐accredited standards development organization has been actively turning state of‐the‐art research and industry practices into a suite of design and installation standards. In 2004, AISI released updates to its General Provisions, Header Design, Prescriptive Method and Truss Design Standards. In 2005, the AISI completed a Code of Standard Practice. A Steel Stud Brick Veneer Design Guide and a Cold‐Formed Steel Framing Design Guide have also been developed to assist practicing structural engineers and architects to design cold‐formed steel framing systems. This presentation will provide an introduction to these significant industry documents.

Select this Article		Industry‐Wide Innovative Steel Framing Products for Curtain Walls Nabil A. Rahman, Ph.D., P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)12 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Several innovative products have been developed by cold‐formed steel manufacturers to facilitate the accommodation of curtain wall architectural requirements into the buildings. New stud products focused on increasing stud stiffness‐to‐weight ratio, minimizing the thermal bridging of the studs, and enhancing its acoustic performance. This resulted in the creation of some unique stud shapes. Innovative bridging products added extra functions such as easier attachment to studs and accurate stud spacing. Attachment clip connectors for head‐of‐wall and by‐pass conditions provided means for accommodating building deflections due to live loads and/or wind uplift, as well as accommodating drift displacements due to earthquakes.

Select this Article		Functional Isolation Concept in Curtain Wall Design Raymond Ting ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)13 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The primary purpose of a curtain wall system is to protect the building interior against the exterior natural phenomena such as sun exposure, temperature changes, earthquake, rain, and wind. This protection can be separated into two major categories, namely structural safety and interior environmental control. The structural safety problems include failures of wall component, wall facing material, and fasteners. The interior environmental control problems include excessive energy loss, noise control, mold growth, interior water condensation, and water leakage. It is essential to maintain this protection for the life of the building ideally without periodic repairs or total renovation. Unfortunately experience indicated that the life of a curtain wall system can not outlive the building life due to complicated and intertwined multiple functional requirements of a curtain wall system. For example, sealing functional failure due to sun exposure and/or sealant line stress fatigue caused by various structural movements of wall components and building frame (such as thermal expansion or contraction, wind load deflection or rotation, dead load deflection, inter‐floor live load deflection, and inter‐floor story drift) could produce a chain of functional failures, for example, water leakage leading to wetting of insulation material (energy loss) or mold growth (sick air building) or rusting of connection system leading to structural failure. The maintenance and renovation cost of the curtain wall system has a very significant impact on the life‐cycle cost of the building. This cost impact can only be evaluated if the durability of all curtain wall functions can be determined. Unfortunately, little has been done in this regard due to the complexity of the intertwined curtain wall functions. This paper highlights the possibility of using Functional Isolation Concept (FIC) in designing a curtain wall system to greatly reduce the interferences among the various curtain wall functions. Continuing development of FIC in the future may lead to a reliable method of evaluating the cost impact of a curtain wall system on the life‐cycle cost of a building.

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MECHANICAL/ELECTRICAL SYSTEMS

Select this Article		Innovative Design Solutions for Burn Intensive Care Units Isabelle A. Lavedrine, CPhys MInstP and Patric Thomas, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)14 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Burn ICUs have among the most stringent design criteria for patient rooms in hospital design. Communication between the architect designing the room layout and the mechanical engineer designing the ventilation system is critical to ensure that their design converge to meet the tight comfort criteria. The Computational Fluid Dynamic analysis played an important part in this process for a University Medical Center, and a physical test of the final set‐up confirmed the design and validated the CFD model. In a Burn ICU, the patient is weak and sensitive due the high body surface temperature caused by the burns. To ensure comfort for the patient, strict design criteria are to be met for both air speeds and temperatures. Velocity at the patient is not to exceed 50fpm (0.25m/s), and the environmental temperature around the patient is to be kept at 70 degrees Fahrenheit plus or minus 2 degrees (21.1 degrees C ± 1 degree C) in cooling mode. It is the role of the mechanical engineer to ensure that these criteria are achieved inside the Burn ICU. Therefore communication with the architect who designs the room layout is crucial. The Computational Fluid Dynamics (CFD) analysis played a very important part in facilitating the communication with the architect. Several design configurations were modeled and investigated to optimize layout and ensure that comfort criteria are still maintained. The results from the modeling helped provide a visual tool that the mechanical engineer could use to convey the alternatives to the architect about the position of the supply grilles and radiant panels and the effect on the flow and temperature patterns. Finally, a physical test was carried out to confirm the final set‐up of the Burn ICU. The CFD analysis enabled to restrict the number of tests to be carried out, ensuring faster testing and suppression of unnecessary tests. The results between the CFD analysis and the physical tests are being compared to further the validation of the numerical method. The two techniques helped to design a better room for the patient.

Select this Article		Using Construction, Operations, and Maintenance Knowledge to Better Coordinate Mechanical, Electrical, and Plumbing Systems in Buildings Thomas M. Korman, P.E., M.ASCE and C. B. Tatum, P.E., F.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)15 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The coordination of mechanical, electrical, and plumbing (MEP) systems has become a major challenge for complex buildings and industrial plants. MEP coordination involves locating equipment and routing connecting elements for each system to avoid physical interferences, allow full system functionality, and comply with several types of criteria. Current MEP coordination practice uses a process of sequentially overlaying and comparing drawings from multiple systems, during 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. More significantly, knowledge critical to the project life cycle is overlooked during the process. Using examples from several case studies, this paper demonstrates how integrating construction, operations, and maintenance knowledge into the process of MEP coordination can improve the design of mechanical, electrical, and plumbing systems in buildings. The results of this research provide a foundation for a revised work process, using information technology, and assist in multi‐discipline coordination efforts.

Select this Article		Office Lighting for Lighting Education Chrysanthi Mishek and Clarence Waters, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)16 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The use of faculty offices to demonstrate lighting systems is an innovative way to enhance lighting education for students. The lighting of Peter Kiewit Institute 206A, a faculty office, was designed with the intent of exposing students to different illuminated environments and techniques. The lighting systems to be described include direct, indirect, combined direct‐indirect, wall lighting, and a theatrical scrim ceiling. The direct and indirect lighting systems expose students to the visual impact of these systems and combination of them. The wall lighting provides direction of focus. The theatrical scrim ceiling is used to expose the infrastructure when surfaces above the ceiling are illuminated and to act as a ceiling when illuminated from below the ceiling. This paper will include a detailed technical description of the lighting in the space, photographs, and measurements of the space.

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NOISE AND VIBRATION CONTROL ‐ 1

Select this Article		Improved Methodologies for the Prediction of Footfall‐Induced Vibration Michael Willford, Caroline Field, and Peter Young ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)17 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The increasing use of high strength materials, modern architectural expression and the desire for high‐tech building environments has led to an increasing need to consider vibration performance as a key design objective for buildings and other structures. Human footfall is a significant source of vibration and if its effects are not assessed accurately during the design of a facility the workspaces may be rendered unusable for sensitive equipment or uncomfortable for occupants. In view of the importance of achieving an acceptable vibration environment in modern facilities it is perhaps surprising that the design methods employed by most structural and vibration engineers comprise very simple and semi‐empirical hand calculations based on research available in the 1970s. In order to provide clients with greater confidence in the performance of their structures Arup has developed new and more accurate ‘performance based’ prediction procedures incorporating recent comprehensive experimental research into footfall forces, and taking advantage of the capabilities of modern design‐office computer software. The new methods are not limited by the approximations and inaccuracies inherent in the old empirical approaches, and extensive calibration against field measurements has shown them to be far more reliable than other methods currently in use. This new approach can bring substantial cost benefits in some cases as well as reduction in risk through accurate quantification of performance. This paper describes the methodology in detail and compares with predictions from other methods and measured data.

Select this Article		Effects of Noise on Productivity: Does Performance Decrease Over Time? Jessica Errett, Erica E. Bowden, Marc Choiniere, and Lily M. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)18 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Most people at one time or another have found themselves irritated or distracted by the background noise in a building. The irritation might have resulted in minor aggravation or may have been dramatic enough to hinder their work. This leads us to ask whether occupants are increasingly aggravated by noise the longer they are exposed to it, or if they naturally habituate to their acoustic environment. In an effort to answer this question, a study was completed in the “Indoor Environment Lab” at the University of Nebraska. This lab resembles a typical office and was specially constructed to be acoustically and thermally controlled. Subjects completed 38 total hours of testing in the lab over multiple days, during which time they were exposed to several background noise conditions over 20, 40, 80, and 240 minute trials. During the trials, subjects completed a variety of performance tasks and answered questions about their perception of the noise, the thermal environment and various other factors. End results aid in understanding the prolonged effects of typical heating, ventilating, and air‐conditioning (HVAC) noise on worker productivity and annoyance.

Select this Article		Measuring Sound Power in Ducted Heating, Ventilating, and Air‐Conditioning (HVAC) Systems for Use in Verifying Acoustical Prediction Methods Steven R. Ryherd and Lily M. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)19 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper discusses issues regarding in‐situ methods of obtaining sound power at a point in a heating, ventilating and air‐conditioning (HVAC) duct system. Such a method is being used as part of a larger investigation on acoustical prediction methods to allow for comparison of measured data to results from attenuation predictions of individual duct elements, such as elbows or dampers. Sound propagation in HVAC duct work is complex. Any measurements of sound energy in the duct must address the characteristics of sound propagation in ducts, end reflections, and air turbulence. Investigations are being conducted to understand the extents to which these acoustical issues affect measurement results. The study provides a better understanding of sound propagation in HVAC ducts for future investigation of acoustical prediction methods.

Select this Article		Appropriate Characterization of Background Noise Levels in the Workplace Erica E. Bowden and Lily M. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)20 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Overall loudness is not the only quality of indoor background noise that affects occupants. The distribution of noise across frequency (pitch), whether or not the noise contains tones, and whether or not the noise changes over time must also be considered. There are several indoor noise criteria systems available to quantify the background noise in rooms, but many of them do not account for these factors. These systems are commonly used by architects and engineers, and often incorporated into manufacturer's data, design guides, and standards. There is much debate over which of the criteria systems best reflect how occupants will respond to noise. To examine these issues, an extensive study is being completed at the University of Nebraska investigating the effects of various types of air‐conditioning noise on occupant productivity and perception. Results from performance tests and questionnaires are used to evaluate a number of these noise criteria systems. Specific implications of this project on characterizing noise in the workplace will be discussed.

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NOISE AND VIBRATION CONTROL ‐ 2

Select this Article		Steady‐State Diffuse Acoustic Radiosity for Sound Level Prediction in Rooms Ralph T. Muehleisen and C. Walter Beamer, IV ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)21 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The prediction of sound levels of noise and acoustic signals in rooms is a seemingly simple process. In practice, predicting sound level prediction in rooms is done either with simple diffuse field theory, one of several empirical formulae, or with complicated and time consuming modeling using an acoustic ray tracing program. The first two methods are applicable only to a limited number of rooms and are often misused. The last method is usually not employed because of the time and cost involved. To reduce the time and cost associated with computer modeling but provide a more accurate solution than that provided by simple diffuse field theory or empirical models, the acoustic diffuse radiosity method has been developed for the prediction of steady state sound levels in rooms. In the acoustic radiosity method, the boundaries of a room are broken into elements and the energy exchange between the patches is computed. This energy exchange is a computation that is source and receiver location independent so once it has been accomplished, computation of sound levels at a variety of source and receiver locations is quickly accomplished. The ability to compute the room surface interaction only once reduces computation time for accurate prediction of sound levels by orders of magnitude compared to acoustic ray tracing which is both source and receiver location dependent. In this paper the steady state diffuse acoustic radiosity method is introduced.

Select this Article		Room Acoustics Computer Modeling: Study of the Effect of Source Directivity on Auralizations Michelle C. Vigeant, Lily M. Wang, and Jens Holger Rindel ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)22 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Auralizations are very useful in the design of performing arts spaces, where auralization is the process of rendering audible the sound field in a space, in such a way as to simulate the binaural listening experience at a given position in the modeled space. One of the fundamental modeling inputs to create auralizations is the source directivity. Standard methods involve inputting the measured source directivity, calculating the impulse response and convolving it with a single channel anechoic recording. An initial study was conducted using this method and the results showed significant differences in reverberation time and clarity index when using a directional versus omni‐directional source. Further research was conducted focusing on an alternative method of modeling source directivity that involves multi‐channel anechoic recordings to create auralizations. Subjective tests were conducted comparing auralizations made with one, four and thirteen channels, with three different instrument types and subjects rated differences in realism. An analysis of variance (ANOVA) was carried out to determine the effect of the number of channels and instrument on realism. The primary result from this study was that subjects rated the auralizations made with an increasing number of channels as sounding more realistic, indicating that when more accurate source directivity information is used a more realistic auralization is possible.

Select this Article		A Review of Diffuse Reflections in Architectural Acoustics Jonathan Rathsam and Lily M. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)23 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Diffuse reflections have received increasing attention in architectural acoustics over the past quarter century. The term diffuse refers to non‐specular directions. This paper identifies three mechanisms that cause diffuse reflections. Practitioners have found that changing specular reflections into diffuse reflections can reduce noise and echoes both indoors and outdoors. Developers of acoustical modeling software have also found that modeling diffuse in additional to specular reflections produces more accurate predictions. The final portion of this paper presents results for a study of scattering coefficients in acoustical modeling software.

Select this Article		Room Acoustics in Coupled Volume Spaces David T. Bradley and Lily M. Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)24 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The study of sound in the built environment is finding more awareness in the 21^st century. As this awareness has increased, and as computing power has grown, the method of computer modeling for studying room acoustics in such settings as classrooms, offices, and performances spaces has taken great strides in recent years. Of particular interest has been the study of the coupled volume space due to its unique ability to provide contrasting acoustical phenomenon. A coupled volume room is generally defined as a space consisting of a large main volume containing high levels of sound absorption connected through small sonically transparent apertures to a smaller coupled volume with lower absorption. When a sound source is placed in the main volume, this configuration may lead to sound energy being trapped in the coupled volume, which is then released back into the main space at a later time. The delay in sound energy from the coupled volume results in a double‐sloped sound decay in the main volume, resulting in intriguing acoustical phenomenon not typically seen in single volume spaces. The real world application of this type of space is most commonly found in concert hall settings. The use of computer modeling to study this relatively complex type of space is a comparatively new development, and the limits of the method have yet to be fully explored. This research focuses on determining the effects of the architectural parameters, absorption level and aperture size, on the room acoustics in coupled volume spaces. A coupled volume concert hall computer model was constructed and analyzed in order to determine these effects. Comparative analysis of several configurations of the model reveals that increased absorption in the coupled volume decreases double slope effect, while the effect generally peaks for a relatively small aperture opening size.

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PANEL DISCUSSION ON CASE STUDIES AND ARCHITECTURAL ENGINEERING

Select this Article		Two Case Studies in Architecture, Engineering, and Construction: The First National Bank Tower in Omaha, and the Durham Research Center, University of Nebraska Medical Center, Omaha William Borner, Professor of Architecture and Bruce Anderson, Ph.D. Student in Architecture/Education Program ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)25 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper is about a series of three Case Studies done primarily by 5^th and 6^th year students of architectural design at UNL under the auspices of the AIA Case Studies Initiative. The first (First National Bank of Omaha) was completed in the summer of 2004 and was successfully submitted and selected as one of only seven case studies on the national AIA web page (www.aia.org/ed_case studies). A second Case Study was completed (Durham Research Center at UNMC, Omaha) in the summer of 2005, and has been submitted to the AIA Case Studies Initiative. We are awaiting notification if it has been selected for inclusion on the national web page. A third Case Study beginning this spring 2006 will study the Peter Kiewit Institute of Information Science, Technology and Engineering at UNO, Omaha. This paper discusses the highlights of these two completed Case Studies from the perspective of the faculty, the students and the large firms themselves, and discusses lessons learned and preparations for the third Case Study in the spring semester 2006, to be submitted in the summer as well.

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STRUCTURES: DIAGNOSTICS AND MATERIALS

Select this Article		Assessment of Significances of Building Failure Induced by Foundation Failure: Façade Failure and Moisture Problem Jun Lin and D. Scott ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)26 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Numerous technologies and materials have been developed to protect structures from failure. Yet they are comparatively expensive. And, in some cases they were useless when correlative types of failures have a low probability of occurrence. Thus, failure analysis is necessary for a cost‐efficient investment, as it locates the failures that should be, and are worth being controlled by employing preventive measures. In this paper, 36 cases of 3 types of building failures: Foundation Failure, Façade Failure and Moisture problem were classified into 10 subsections and analyzed to discover the potential risks in a building investment. As found, moisture related building failure is the costliest type of failure among these 3 categories. And, in further analysis, SBS caused by the moisture problem was found to be the most significant subsection among those 10 subsections, which should be thoroughly considered in the building investment.

Select this Article		Dual‐Purpose Hollow Structural Sections for Building Slab Construction Indrajit Ghosh, M.Sc (Struct, UK), P.E., F.ASCE, M.ASCE/SEI ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)27 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract In a conventional method of design and construction of building floors, structural beams such as steel wide‐flange sections or concrete beams are generally used to support concrete floors. Heating, ventilating and air conditioning (HVAC) ducts are hung from these beams. This paper introduces the concept of “dual‐purpose beams” that integrates structural floor supporting system and HVAC ducts.

Select this Article		Influence of Concrete Creep on Durability and Reliability Characteristics of Prestressed Composite Slabs G. Sossou ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)28 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This theoretical and experimental study relates to the details of a unified design and tests procedure for analytical prediction of various durability, reliability and quality structural characteristics of steel‐concrete composite slabs, prestressed in both directions. This analytical procedure is aimed at predicting the quality, stiffness, strength, reliability and durability at the planning phase, the nonlinear creep behaviour of these said composite members. This present ongoing study is so actual, as it is recognized that little information is available on the time dependent factors like the matrix (concrete) creep, shrinkage and loss of stress, in relation to bi‐directional prestressing of reinforced steel‐concrete composite slabs, with high yield tendons, subjected to long‐term service loads. Deformation laws of thin isotropic concrete matrix membranes in a uniform stress state have been applied to solve the composite slab's problems.

Select this Article		Fabric‐Formed Concrete Panel Design Robert P. Schmitz, P.E., M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)29 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Concrete wall panels have traditionally been cast using a rigid formwork. Straightforward methods of analysis and design are available for the traditionally cast concrete wall or floor panel. This is not so for the panel cast in a flexible fabric formwork. To date, no design procedures or methods to predict the deflected shape of a fabric cast panel have been developed. This paper introduces a design procedure that allows one to design a fabric cast concrete panel. A four‐step procedure for analytically modeling a fabric formwork is developed employing the structural analysis program ADINA to analyze the formwork and the concrete panel cast in it. The final panel form, function and performance of the fabric membrane and the reinforcement of the panel for design loads all add to the complexities of the panel's analysis and design. Analytical modeling and design techniques presented in this paper will allow the design community another way to express themselves using a flexible fabric formwork. No longer will designers feel constrained by the limitations imposed by using a rigid formwork.

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STRUCTURAL ANALYSIS AND BEHAVIOR

Select this Article		Experimental Evaluation of a Sacrificial System for Masonry Infill Walls Mohammad Aliaari and Ali M. Memari, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)30 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The Seismic Infill Wall Isolator Subframe (SIWIS) system is developed for use in building moment frame systems with masonry infill walls in order to prevent damage to columns or infill walls due to infill‐frame interaction during potentially damaging earthquakes. Because of the conventional tight‐fit construction within structure frames, infill walls generally participate in resisting wind and seismically induced loads. Although beneficial during wind loads and minor earthquakes, the interaction of infill wall and frame during strong events can damage the wall or the frame if the infill wall is not designed as shear walls. The SIWIS system can be designed as a “sacrificial fuse” to allow infill wall‐frame interaction under wind loading and minor‐to‐moderate earthquakes for reduced building drift, but to disengage their interaction under severe damaging events. An experimental testing program was carried out to test the concept of the SIWIS system. The experimental program included a series of component tests on three different designs for fuse element materials including concrete disk, steel disk, and lumber disk. These tests were followed by a series of in‐plane static pushover tests on a scaled two‐bay three‐story steel frame equipped with SIWIS fuse elements. This paper discusses the experimental program and presents the results of the tests.

Select this Article		Rational Analysis of Prying Action in Tension Bolted Connections H. Estrada, P.E., Ph.D. and J. L. Huang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)31 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of the work presented in this paper is to modify the current design approach used to determine prying action in tension steel bolted connections. Most studies approach the analysis by assuming the location of the prying force resultant to be at the edge of the connecting member flange. We modified this design approach through a numerical analysis using a Finite Element Analysis (FEA) program, I‐deas, to obtain the relationships between prying action and other factors. Depending on these relationships, we modified the current equations following the results of our investigation to obtain a “better” estimate of the connection strength for a given steel connection geometry.

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STRUCTURAL DESIGN OF BUILDINGS FOR SERVICEABILITY

Select this Article		Simulation of the Alfred P. Murrah Federal Building Collapse Due to Blast Loads Hatem Tagel‐Din, Ph.D. and Nabil A. Rahman, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)32 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Many trials have been made to numerically simulate the Alfred P. Murrah Building bombing event using Finite Element Method. These trials were based on removal of one of the main supporting columns to investigate the generated internal forces and the possible deformations in other elements. However, these trials could not simulate real bomb explosion and automatic detection of the failed columns and floor slabs. Furthermore, the finite element analysis could not continue to model separation of failed elements, collision between structural elements till complete collapse. In this paper, a new technique, Applied Element Method (AEM), is used to simulate the collapse process of the Murrah Building. The bomb weight and location are considered in the simulation. Free‐Field blast wave was assumed. The building dimensions, reinforcement and material properties were taken into account. The simulation shows real time analysis of the building performance since the blast occurs, failure of one of the supporting columns, and the failure of the supporting transfer girder till partial collapse of the structure. Two more cases were studied; the bomb was moved to the corner of the building and increasing reinforcement of the transfer girder to check building performance during these events. Results indicate that design firms, engineers, and insurance companies now can judge the safety of existing structures when subjected to extreme loads and to study the safety of proposed structures prior to their construction.

Select this Article		A Unique Vibration Serviceability Case Study of a Complex Structure Kelly A. Salyards, Linda M. Hanagan, PhD, P.E., and Christopher A. Kim ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)33 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract When several occupants of a newly constructed academic building raised a concern of disturbing vibrations in several of the third floor offices, an investigation ensued that aimed to capture and characterize this disturbing vibration. A remote monitoring system was utilized to monitor the offices of interest and the offending vibration was finally recorded. The recorded data indicated that this vibration was not a typical serviceability issue due to walking. The study that followed examined the dynamic characteristics of the floor structure through dynamic testing and consequently several unusual vibration sources were explored ranging from wind or traffic to mechanical equipment to an often overlooked human excitation best described as leg jiggling. Some of the findings related to this unusual and interesting case study are described in this paper.

Select this Article		State‐of‐the‐Art Protection against Severe Storms H. Estrada, P.E. and E. Kiesling, P.E., Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)34 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Safe rooms, or in‐home storm shelters, are fast becoming integral components to households in some extreme‐wind prone areas such as tornado alley and the hurricane susceptible coastlines of the United States. The main purpose of storm shelters is to protect their human occupants during extreme‐wind events, not to protect possessions. For this reason, shelters tend to be relatively small, thereby occupying only a fraction of the floor plan of a home. Because of their size, their assimilation into new and existing constructions is relatively simple and relatively inexpensive. The additional cost of a storm shelter may be justifiable even though the risk to human life compared to other tragic events is relatively low. This paper presents an overview of the analysis and design of in‐home storm shelters. In particular, we concentrated on stability, strength, and impact‐worthiness of the overall system. We also discuss the effectiveness of existing safe room designs. The paper concludes by summarizing some economic considerations that will foster shelter utilization.

Select this Article		Drainage: The Essential Ingredient in Basic Parking Structure Durability Design Robert C. McConnell, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)35 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Parking structures are constructed of concrete and steel and are essentially exposed to the elements. As such, they have a life cycle similar to that of a highway bridge. A parking deck can be exposed to rain, snow, extreme high and low temperatures, road deicing salts, and just about anything else that can cause deterioration in an exterior environment subject to vehicle traffic. The deterioration typical in parking decks can be attributed primarily to water. Standing water will accelerate deterioration, especially if it is contaminated with road deicing salt. If the standing water freezes, it represents a hazardous condition for both pedestrians and vehicles. To counteract the problems caused by standing water, a well‐designed drainage system is essential. A brief explanation of the deterioration mechanisms typical in concrete parking structures is presented herein, along with suggestions to mitigate deterioration. The focus of the discussion is excellent drainage, which is generally the most effective and least expensive durability feature that can be incorporated into a parking structure design. Excellent drainage design is not a simple proposition and is often overlooked. This can lead to the necessity of expensive repairs in the future. Finally, suggestions for designing excellent drainage are discussed, incorporating guidelines from, among others, the American Concrete Institute, the National Parking Association, the American National Standards Institute, and extensive personal experience.

Select this Article		QA/QC Testing for Concrete in Harsh Environments Karthik Obla, Ph.D., P.E., Colin Lobo, Ph.D., P.E., and Lionel Lemay, P.E., S.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)36 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Quality assurance and quality control testing for concrete is becoming more complex. In addition to typical concrete tests for strength, slump and air content, there are other performance‐based tests that measure such properties as permeability and resistance to chemical attack. Many of these test methods are complicated and sensitive to variability in sampling and procedure. Some tests are best suited for pre‐qualifying concrete mixtures while others are better suited for field acceptance. This paper describes a general concept of specifying and acceptance for concrete in harsh environments. It will provide guidance on which tests to specify, the precision of each test and the appropriate acceptance criteria.

Select this Article		A Whole Building Cost Perspective to Floor Vibration Serviceability Linda M. Hanagan, PhD, P.E. and Melissa C. Chattoraj ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)37 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract When selecting between lightweight steel joist floor systems and heavier composite or non‐composite systems using rolled steel beams, two issues are generally considered to be in competition. These two considerations are cost and vibration serviceability. In general, it is thought that even though the joist floor is more prone to disturbing vibration levels, it is sometimes a better choice based on economy. This paper explores a whole building cost approach to assessing the economy of the lighter joist system relative to its rolled beam competitor. It is illustrated that other building systems, such as fire protection, are affected by the selection of the floor system, thus affecting total building cost. The end result is a closing of the cost gap between heavier rolled beam floors and lighter joist floors.

Select this Article		Deflection Control for Serviceability of Reinforced Concrete Floor Systems Young Hak Lee and Andrew Scanlon ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)38 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Design of concrete floor systems for deflection control has for many years relied on empirical rules of thumb for selection of span to depth ratios or simplified deflection calculation procedures and empirical deflection limits based on previous experience. With increasing use of high strength materials and advanced analytical techniques there is a need to develop a more rational approach to design for deflection control. This paper reviews current practice for deflection control and suggests an alternative to the ACI Code minimum thickness factors to account for a wider range of design variables. The paper also proposes the use of utility theory as a basis for proportioning members to provide acceptable deflection control. The procedure reduces to the minimization of total cost consisting of initial construction cost and the cost of serviceability failure. The cost of serviceability failure includes consideration of uncertainties in loads and response to load (including time‐dependent effects) through Monte Carlo simulation and non‐discrete thresholds for serviceability limit states. Construction issues related to deflection control also discussed.

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PLANNING METHODS AND APPLICATIONS

Select this Article		A Multi‐Disciplinary Approach to Conceptual Design of Innovative Infrastructure Systems Joseph P. Hanus, Lawrence C. Bank, Gerardo I. Velazquez, and James C. Ray ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)39 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract A conceptual design approach is presented that was applied in a multi‐disciplinary project to develop innovative solutions for the US Army's Future Combat System to negotiate 4‐meter gaps on the battlefield. The design approach focused on seven steps that were founded on three specific techniques. The techniques included a dual approach to developing project objectives, a two‐dimensional model based on risk and return to evaluate conceptual concepts, and a controlled convergence with iterative concept generation and selection. It is proposed that this conceptual design approach may be beneficial to other projects because of the commonality with the objectives associated with conceptual design, innovative solutions, and infrastructure systems. The development of unique design methods is necessary to meet a challenging design environment that seek innovative solutions for infrastructure systems. The conceptual design approach presented and illustrated in this paper addresses this challenge.

Select this Article		Practice‐Facilities Development and Ideas Management‐Implications on Education Kolialum Devanathan, M.ASCE, M.AEI and Pushpa Devanathan, Asst. Professor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)40 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Architecture as a profession, from its primordial beginning was concerned with the entire field of built environment rather than a question of mere shelter. Architecture was seen as a practical science of building or construction and its decorative expression was interpreted for its stylistic consistency to classify and categorize the same. The development of modernistic architecture will be a revolutionary step for Indian architects to redefine the scope of architecture incorporating comprehensive activities and services at various scales of built environment. This enables architects to reorient their creativity as specialists. The simplest way of defining architects is as professionals possessing set of skills, technical as well as managerial and artistic in nature. There is some perceived inadequacy in the training and education imparted to architecture students as they adapt to the changing context of practice and requirement, this problem of primary concern is to be addressed in the future. A significant amount of time is spent on management activities in the practice of architecture for which the student is inadequately prepared in the university. It is clear that to offer professional service with value additions, educational institutions need to be dynamic and supportive. This means to offer improvised service is to integrate the organizational change and building designs, the study of appropriate advanced technological methods and materials. Restructuring architectural education to make it more responsive, at the grass roots levels, would mirror this.

Select this Article		Front End Planning for Buildings G. Edward Gibson, Jr., Ph.D., P.E., Kyle T. Irons, and Michael P. Ray, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)41 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Front End Planning is arguably the single most important process in the building project life cycle. Known in architecture terms as programming, schematic design, and design development, this phase of the project is many times poorly performed leading to less than successful outcomes. Front End Planning is focused on creating a strong, early link between the business or mission need, project strategy, scope, cost, and schedule and maintaining that link unbroken throughout the project life. Anecdotally, many companies admit that good front end planning is rare, however it is required for every building project. This paper will focus on past and current front end planning research conducted by researchers at The University of Texas at Austin. The results of over a dozen case study evaluations will be presented from an ongoing research investigation from projects worth over $1.5 billion. Additionally, statistics on front end planning effectiveness, including the relationship between front end planning and cost and schedule growth, will be shown using a sample of projects worth several billion dollars. Key findings and advice from this study will be provided for industry practitioners.

Select this Article		A Study on the New Design Theory for an Age of New Paradigms Motoyuki Minakami, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)42 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract A paradigm shift in many areas will inevitably occur in the face of the global scale transformation of social systems: the appearance of global environmental problems, the worldwide information revolution, and globalization for example. Design is an extremely broad concept, but it is a grim reality that the design of all things greatly transforms the performance that systems must provide, and there is a growing demand for high performance ideal design needed to meet the above challenges. What kind of methodology should we apply to perform better design in this age of new paradigms? The purpose of this study is to discover what flow must guide our design work to enable us to achieve designs more ideally suited to this age of great change and to search deeply for the ultimate grounds on which we can construct the foundations of this design theory.

Select this Article		Means of Egress Building Code Compliance Diagrams Khaled Nassar and Mohamed El‐Nahas ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)43 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Means of egress can be defined as “a continuous and unobstructed path of travel from any point in a building or structure to a public way” [IBC]. This paper presents a new way to represent and check for means of egress compliance automatically (means of egress code compliance diagrams (MECC) for the building). Additionally, a prototype computer tool, MEC³ is developed to help in generating and checking the diagrams. This tool is presented in this paper also.

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CODES AND STANDARDS

Select this Article		Assessment of Shoring Systems for Safety of Elevated Slab Formwork Using Nested Factor Designs Jin‐Lee Kim, M.ASCE ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)44 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The objective of this paper is to present the results of a statistical analysis for the performance of the shore slope to determine the stability of metal single post shores in high‐clearance elevated slab formwork. Considering the potential collapse of elevated slab formwork during concrete placement due to deficiencies in regular vertical shores, the assessment of shoring system for safety is significant. There is no specified slope tolerance regulation for shoring systems since one recognizes all post shores being plumb from a common sense standpoint as well as the existing regulations. Therefore, it is necessary to assess the accuracy of the shoring installation. In doing so, nested factor designs have been conducted to compare the stability of low‐clearance shoring systems to that of high‐clearance shoring systems, using shore slope data measured on actual construction sites. The average error for the shore slope was 3.156 degrees. Experimental results are inconclusive because there is no difference among the averages of high‐clearance/low‐clearance projects for the shore slope. However, it is conclusive that there is a variation among the locations within high‐clearance/low‐clearance projects. The results of the statistical analysis indicate that the accurate installation of the shore is an important factor for the shoring safety during construction in high‐clearance concrete buildings. It is strongly suggested that the error in the single post shore slope be considered when conducting a structural analysis for shoring systems in high‐clearance elevated slab formwork construction.

Select this Article		Performance‐Based Specifications for Concrete Colin Lobo, Ph.D., P.E., Lionel Lemay, P.E., S.E., and Karthik Obla, Ph.D., P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)45 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Demands on concrete structures are more severe than ever. Engineers, contractors, and material suppliers are being asked to design and construct buildings that are taller, larger, and last longer than in the past. Traditional prescriptive specifications for concrete are no longer effective and the concrete construction industry is moving towards performance‐based specifications. This paper will explore how performance‐based specifications are being used to implement innovative products such as high‐performance concrete, self‐consolidating concrete and high‐strength concrete.

Select this Article		The Perception of Risk in Performance‐Based Design of Buildings Benjamin Thompson and Lawrence Bank ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)46 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract As buildings have become larger and come to house more people, and political and societal issues have become more complex, risks associated with occupying buildings have changed. In particular, since the terrorist attacks of 2001, anxiety levels and perceived risks of building occupants (especially occupants of tall, high‐profile buildings) have increased. These perceived risks include terrorist attacks, natural disasters, the possibility of bomb threats and catastrophic fires. Since building codes are in existence for the benefit and protection of the public, it seems reasonable that the codes should take into account the perceptions and fears of the general public when designing for all hazards. Psychometric risk perception is already incorporated into building design codes and performance‐based design (PBD) methods for such hazards as earthquakes and fires—explicitly in some cases, implicitly in others. Codes for designing structures have historically been prescriptive. There is a level of performance implicit in prescriptive design, but PBD makes performance levels explicit and predictable, and allows for designs that surpass the minimum level of performance required by prescriptive codes, and for designs that protect against a broader range of hazards, including explosions and terrorist attacks. PBD also allows owners and designers the flexibility to choose performance levels appropriate to their situations, and to make informed trade‐offs between the costs and ‘acceptable’ risk levels.

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EDUCATION AND ETHICS

Select this Article		Development of a New Architectural Engineering Program at Texas A&M University‐Kingsville H. Estrada, P.E., Ph.D. and W. Heenan, P.E., D.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)47 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents an overview of the development and implementation of a new degree program in architectural engineering at Texas A&M University‐Kingsville. The development component of the program included preparing a proposal to appropriate state agencies for approval and development of curriculum requirements; the proposal was approved in July of 2005. After the approval of the program, the implementation component included securing space for the laboratory facilities, recruiting faculty and students, starting the preparation for accreditation by the Accreditation Board for Engineering and Technology (ABET), and begin offering courses. The first course in the degree plan is being offered in the fall semester of 2005, Computer Based Graphics and Design. Current enrollment figures indicate that the program will be very successful in attracting students; even before it was approved in July several students had enrolled in other engineering disciplines in anticipation of the program being approved. The first cohort of students entails fifteen. The program will be a traditional four‐year engineering degree program requiring 131 semester credit hours of coursework sufficient to satisfy all the accreditation requirements of ABET. The curriculum includes coursework in communications, social science and humanities, mathematics and science, engineering fundamentals, and the three basic curriculum areas of architectural engineering: structures, building mechanical and electrical systems, and construction/construction management.

Select this Article		Integrating Architecture and Structural Design in the Comprehensive Design Studio J. M. Homer, AIA ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)48 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract For many architects, the expression of structure has been a primary factor in the generation of space and form. In fact, many architectural historians distinguish the two primary approaches to architecture as either space articulated by expressed structure (rationalist architecture) or space generated as a plastic expression divorced from the expression of its structure (formalist architecture). However, too often architects can treat structure as separate from the core values of architecture. Structural design is thought to be necessary only to ensure safety, not to enrich the expression of space. At the same time, many structural engineers can perceive the design of structure purely from a practical viewpoint without exploring its creative potential. This is fostered by professional education that many times separates architects and engineers at the university. The School of Architecture at Oklahoma State University offers a unique symbiotic relationship between architecture and engineering by combining these two related disciplines completely within the structure of the school. Both five‐year professional programs are essentially identical during the first two years allowing students to experience the core issues of both programs before making a career choice. AE students take design studios and architecture students are required to take many of the same engineering‐science based structures courses designed to meet rigorous ABET requirements. Professors of each program work closely together in designing both curriculums. AE professors interact with all students on several projects in the lower division design studio courses, and one of the upper division design studios is co‐taught by four faculty members, three architects and one engineer. This Comprehensive Design Studio was recognized by the National Council of Architectural Registration Boards (NCARB) as the 2004 NCARB Grand Prize winner as the best professionally oriented architecture course in the nation. The unique relationship between the two programs and the shared capstone experience in the Comprehensive Design Studio offer an opportunity to explore the potential of structural expression in architectural design, but are we taking full advantage of that opportunity? I would like to share my experiences in teaching this studio, discussing both successes and failures, while exploring precedents we might use to promote the incorporation of structural expression and order into architecture.

Select this Article		Enhancing Architectural Engineering Capstone Design Courses through Web‐Based Technologies Jonathan U. Dougherty and M. Kevin Parfitt, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)49 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Given the advancements in information and communication technologies and the significant opportunities for effective integration of such technology into academic environments, the Department of Architectural Engineering at Penn State (Penn State AE) has established and continues to refine a framework for the use of web‐enhanced protocols in their yearlong capstone design course sequence. This paper will address the curriculum development and representative course enhancements associated with the framework, while showcasing various elements of the student‐centered learning environment. In addition, an overview of the web‐enhanced capstone design model being used at Penn State will be discussed. The use of web technology has provided a means for improving course management by the instructor, increasing the visibility of student‐generated projects, enhancing the practice‐based course content, increasing project archives, and emphasizing knowledge partnerships through student/practitioner interaction.

Select this Article		Engaging All Disciplines within the Education Process Shannon Sanders McDonald, AIA ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)50 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract In any built project many different disciplines come together to make the project a success, the team concept is critical. Architects, engineers, construction managers, planners, and developers all have underlying truths basic to their discipline and supported by their learning processes. The architect, as this is how I was educated, is required to study all areas with a broad intent to operate as the check and balance between client and contractor with the first priority the public. This role and broad education assists the architect in learning how to balance the many conflicting issues that arise in the act of constructing our built environment in the hopes that the final built solutions will meet as many private and public needs as possible. Other disciplines are more focused on specific issues of great importance related to the over all success of the project. Broad with a general understanding of the details versus more specifically focused to a particular outcome would be a brief way to describe the architectural education versus the education of other disciplines. Comparing the curriculum of each discipline to see how they interrelate and overlap and allowing these interconnections to occur and overlap within the learning process will assist with the multi‐disciplinary considerations that occur in the “real world”. If each of these learned skills are understood and every skill is valued for its importance to the team a smoother integration of all of our skills toward the goal of long term sustainable environmental success can be achieved. How we engage in understanding the complexity of the issues and the role of each professional during the educational process is one way to create sustaining ethics in our profession. How can more inclusive approaches be supported, encouraged and managed as a respectful learning experience for all within our architectural discipline? This paper discusses some ideas as appropriate ways to enhance sustaining ethics in pedagogy as we respect the ideas of others so that we can truly begin to understand and respect our role in the total world view.

Select this Article		Architectural Detailing: A Teaching Methodology X. Cheng and G. G. Schierle ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)51 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Architectural detailing is primarily left to experience in professional practice rather than formal education. This paper presents a methodology to teach students and young architects architectural detailing, demonstrated on case studies of point‐supported glass (PSG) walls. Glass walls present some of the most complex detailing challenges with potential flaws, ranging from assembly problems to leaks. Yet the complexity presents an opportunity to address flaws. The methodology is based on rules and steps, considering: assembly, installation, tolerance, functionality, and aesthetics.

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LIFE CYCLE COSTS OF BUILDING/INFRASTRUCTURES

Select this Article		Service Life Prediction of Low‐Slope Roofing Components in Buildings G. Morcous and H. Rivard ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)52 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents the development of probabilistic models for the service life prediction of low‐slope roof components (i.e. membrane and flashing). Data used for model development are collected within the Building Envelope Life Cycle Asset Management (BELCAM) research project. The parameters that significantly affect the deterioration of built‐up roof (BUR) membrane and flashing are identified through statistical tests (i.e. correlation analysis and ANOVA). Transition probability matrices of Markov‐chain deterioration models are developed to be used in predicting the future condition of roof components.

Select this Article		Cost Analysis in the Design of Open‐Web Castellated Beams H. Estrada, P.E., Ph.D., J. J. Jimenez, and F. Aguíñiga, Ph.D. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)53 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Open‐web castellated beams have been used for many years, but because of high costs associated with fabrication they have found limited use in the USA. In other countries, however, this type of open‐web beams has found widespread use, primarily in buildings because of great savings in materials and construction costs. Also, the open web of castellated beams can lead to the additional economic advantage of allowing easy, fast, and less expensive installation of conduit and utilities throughout the structure without the need for special hanger supports and without an increase in finished floor elevations. Any savings in steel weight because of the use of these beams are also a positive factor as it relates to the overall supporting structural and foundation systems. In addition to the economic and functional advantages aforementioned, these beams maybe used to enhance the aesthetics of buildings. The purpose of the work presented in this paper is to conduct a detailed cost comparison between open‐web castellated beams and unaltered standard wide flange beams. For castellated and unaltered standard wide flange beams with equal load capacities our investigation shows that castellated beams are more advantageous, making them very attractive for use in buildings. Particularly when considering large projects where the number of required beams is over one hundred, where castellated beams are economically competitive with unaltered standard wide flange beams.

Select this Article		Life‐Cycle Cost Analysis for Selection of Energy‐Efficient Building Components in Lodging Facilities Giovanni C. Migliaccio, Sachin Goel, and James T. O'Connor ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)54 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract This paper outlines a methodology for applying life‐cycle cost analysis (LCCA) for selecting building components in a typical modular and repetitive lodging facility. The study explores available tools, such as energy simulation and building life‐cycle costing software, and identifies a methodology for their application under uncertainty. An analysis of life‐cycle costs for a window system in a typical two‐story economy lodging facility is presented as an example of an application of this methodology. The effect of one design factor, site location, is investigated through a sensitivity analysis, which considers a location for each different climatic area in the United States. Moreover, a contingency analysis is also performed to assess how changes in energy prices will affect the decision process. The charts resulting from the uncertainty analyses provide an interesting insight for decision‐makers.

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BUILDING SUSTAINABILITY/FIAPP

Select this Article		Evaluation of Building Performance University of Missouri‐Rolla (UMR) 2002 Solar House Swarnali Dastider Gosh and Stuart Baur ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)55 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The aim of the study project is to investigate, analyze and compare the performance of University of Missouri Rolla [UMR] 2002 solar house with a conventional house and an ideal house developed by an energy simulation program in terms of energy efficiency. In 2002 UMR built a solar powered house to participate in Solar Decathlon. Presently this house is permanently set up on campus and is used as student housing. This house also provides research opportunities to monitor of the solar house year round. Energy‐10 software [Version 1.6] developed by National Renewable Energy Laboratory was used to evaluate the houses. The software uses a set of passive solar strategies to optimize energy performance of commercial, institutional and residential buildings. It also evaluates day‐lighting, passive solar heating and natural ventilation, lighting and mechanical equipment within the building. It allows the user to calculate energy and cost savings quickly. However Energy‐10 simulation models require modifications as to the shape and form of the model due to its limited choices. For each study model it considers the shape of the building as a complementary rectangular box to develop the virtual model. In this research study few modifications were made to accommodate the limitation of the software. These modifications included use of local climatic data library, replication of original construction methods and materials used in the UMR solar house etc.

Select this Article		Strategic Knowledge Management for Building Engineering and Construction Youngsoo Jung, Seunghee Kang, and In‐Sung Choi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)56 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The purpose of this paper is to propose a methodology that facilitates strategic planning of knowledge management systems (KMS) for the building construction process. The proposed methodology has two major parts; ‘strategic fit analysis’ and ‘disseminative fit analysis’ The former analyzes the KMS areas from a macro perspective, whereas the later assesses them from a micro perspective. By combining these two analyses, effectiveness of the KMSs can be prioritized. Several different detailed techniques for evaluating the KMS areas are then developed for practical application. By applying the proposed methodology to a case‐study company, the corporate/engineering/knowledge strategies was analyzed, capability of construction business functions prioritized, knowledge classified, and KMS areas evaluated. Findings from the entire research process are briefly summarized, and implications and lessons learned for further development are outlined as well.

Select this Article		FIAPP Trends James D. Goedert, Ph.D., P.E. and Pavan Meadati ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)57 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The various phases in the life cycle of a capital project are planning, procurement, construction, operation and maintenance. Lack of interoperability between different software tools is a major problem in attaining continuous data flow between phases. Integrating communication among the various actors of different phases give researchers a new dimension to explore in an effort to increase quality, efficiency and productivity. Implementing FIAPP in the construction industry has gained momentum in Europe and just recently but to a lesser degree in the United States. This paper compares the status of FIAPP in construction industry in European countries and compares that with efforts in the United States and proposes a model for rapid deployment.

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INTEGRATIONS, BUSINESS, MANAGEMENT, AND MARKETING

Select this Article		Managing Delays Caused by Differing Site Condition Khalid Siddiqi, M.ASCE and Abayomi Akinhanmi ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)58 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Remedying site conditions that are materially different from those specified in contract documents is a common source of delay for contractors. The objective of this study was to identify factors that would enable construction contractors to manage delays that are caused due to differing site conditions. The Standard Differing Site Conditions clause is a primary risk allocation clause in all federal and most state government construction contracts that provide for adjustment in the contact price. This clause is also incorporated into the Conditions of Contracts for Georgia school projects. Thirty‐three schools with differing site condition clause from different parts of Georgia were considered in this study. Delays and their causes, due to differing site conditions, were determined through surveys and personal interviews. The outcome of the study indicated that 70 percent of the delays were due to lack of timely and adequate communication between the parties involved. Twenty percent of delays were attributed to lack of trust between owners and their contractors. Remaining delays of about 10 percent were caused by miscellaneous reasons. Persistent and firm follow up of change order requests of the general contractor was found to be a major remedy for reducing the impact of delays caused by differing site condition. The study concluded that prompt and higher level of communication was also necessary for dealing with delays caused by “changed condition”. To remedy the risk associated with differing site conditions the general contractor would normally review durations of all the delay‐dependent activities, which resulted in extension of contract completion date.

Select this Article		A Forecasting Model for Rental Prices of Tower Cranes Yong‐Chan Jung, Seung‐Hoon Lee, Kyo‐Jin Koo, and Chang‐Taek Hyun ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)59 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract In the Koran construction industry, the conventional methods to estimate tower crane rental prices are based on either standard unit prices or historical prices in previous contracts. These methods, however, have had problems not properly reflecting the level of tower crane rental demand. The present paper claims that rental prices are determined by the market prices affected by supply and demand mechanism rather than the two methods mentioned above. In this perspective, this study proposes a regression model by that construction contractors can assess appropriate rental prices of tower cranes considering both the factor of rental demands and adjusting factors. It specifically investigates the contracted prices of T‐type 12‐ton tower cranes which are the most common type of tower cranes in the field of apartment construction.

Select this Article		Integration of Tall Building Systems M. M. Ali, Ph.D., S.E., F.ASCE and P. J. Armstrong, R.A. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)60 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The focus of this paper is to look at the process of integration of tall building systems and how these buildings interact with the city. The design of tall buildings poses a number of challenges for the architect and the engineer. Such design warrants a multidisciplinary approach and integration of architectural function, structural system, vertical transportation, fire safety, energy conservation, and communication systems. It also demands consideration of environmental effects, constructability, and conformity with the urban setting and civic infrastructure. Effective collaboration and a symbiosis of ideas are needed among professionals throughout a tall building project. This is more so for tall buildings because of their enormous scale. It is concluded that integration not only makes the building more reliable and efficient, it is in fact cost‐effective to entwine the various systems together. Illustrative examples are included to shed light on well‐integrated tall buildings and their impact on communities.

Select this Article		Building Integration Solution Ana Bacall, P.E. and Brian Thomson ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)61 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract An elliptical laboratory building with a base of polished gray granite, stainless steel clad columns and glass entryways visually supporting three stories of frameless clear glass curtain wall surmounted by a penthouse of battered curving walls sheathed in stainless steel tiles that enclose mechanical and lab support functions, the proposed new addition to the Forsyth Institute in Boston is also a new prototype for the integrated design of architecture and engineering in laboratory design. Among its many attributes, it: (1) Achieves remarkable efficiency in the ratio of exterior envelope area to enclosed floor area and in its potential operation. (2) Produces an ever‐changing yet efficient pattern of radial lab benches near sources of abundant daylight and view. (3) Derives much of its architectural form and organization from the integration of building architectural and engineering systems within integral strategies to maximize sustainability and energy conservation. Our paper will explore the integration of building systems and their interactions in the design process with particular emphasis on the relationship of architectural form and materiality to mechanical systems for maximization of sustainability and operational efficiency. Subjects will include building orientation, building shape, organization of labs and offices, integration of the building's mechanical and structural systems with its architecture, strategies for sustainability and options for further development of the prototype. We will explain the reasons for choice and placement of equipment within the building and how these choices affect system design including the distribution of chilled and hot water, methods of providing conditioned air, general exhaust, and special (fume hood) exhaust, organization of plumbing risers and lateral distribution for supply, sanitary waste including pH balancing, storm water retention for irrigation, and electrical demand. Our goal will be to demonstrate the importance of design collaboration between architect and engineer from the genesis of building form through the development of detailed documents in creating a solution that is innovative and radically different from the norm, deriving its unique qualities from an attempt to achieve the most comprehensive and compelling solution to the integration of building systems in service to those who will use the building as a platform for creation and discovery of tomorrow's breakthroughs.

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RECOMMENDED PRACTICES FOR CONTROL, COMMUNICATION, AND POWER (C2P) OF CRITICAL FACILITIES 1

Select this Article		A Process for C2P Harmonization: Electrical Standards in North America Brian Haydon, P. Eng. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)62 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Recent events have shown that natural and human made disasters, acts of terrorism and massive technological failures can have a profound impact on the safety and security of people and critical infrastructure. Given the scope of existing codes and standards, the development work sponsored by the ASCE/AEI, “Recommended Practices for Control, Communication and Power (C2P) of Critical Facilities”, to identify ways to improve the resistance of critical electrical infrastructure to disaster, is essential. These recommended practices are intended to augment and not replace engineering requirements promulgated or enforced by the regulatory bodies and authorities having jurisdiction. This work presents a compelling opportunity to embrace a harmonized solution — a single document that will draw on the experiences and lessons of the standards community throughout North America to address issues that are mutually imperative. A harmonized approach is preferred over a national one for several reasons, as this paper will explore. The interests of manufacturers, regulators, specifiers, and users will best be served if Canadian and U.S. representatives undertake the C2P work jointly, with a harmonized document as its outcome. The experience of the standards community in harmonization efforts provides important insights that may be applied to a harmonized C2P process.

Select this Article		Detection of Security Concerns on Data Communications Systems Song Xing, Xiannong Meng, and Xusheng Wang ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)63 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The data communications systems in building today suffer compromises from many different types of attacks. Protection of data and messages that are communicated is the principal object of computer and network security. By far the most important automated protection tool for network and communications security is encryption. As an example, the web service HTTPS transmits private documents between hosts via the Internet over the SSL/TLS connection which uses keys to encrypt data. This paper has presented a scheme to detect the security concerns on current data communication systems via a measurement of the number of HTTPS web servers on the Internet. We presented the conventional Monte Carlo sampling approach to estimate the HTTPS web server density. As a variance reduction technique, importance sampling is introduced, which is a modified Monte Carlo approach resulting in a significant reduction of the effort required to obtain an accurate estimate. We proposed importance sampling approaches to track the prevalence and growth of the HTTPS web service. A thorough analysis of the presented sampling approaches has been performed. An increasing security concerns on the web servers have been detected and discussed.

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RECOMMENDED PRACTICES FOR CONTROL, COMMUNICATION, AND POWER (C2P) OF CRITICAL FACILITIES 2

Select this Article		A Simplified Risk Analyses Method and an Electric Systems Solution to Reliability and Continuity of Vital Service Problems in Critical Service Facilities: A Brief Overview of the Work before the ASCE/AEI C2P Committee James Angelo Ruggieri, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)64 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The unconventional attack on the Alfred P. Murrah Federal Office Building in Oklahoma City, and the assaults and collapse of New York City's World Trade Center Towers have shifted the legislative and regulatory spotlight on Codes and Standards as one element of an integrated protection policy. In his testimony to Congress, the Director of the National Institute of Standards and Technology (NIST) identified the need to “take aggressive remedial action to minimize future losses” of critical infrastructure facilities and systems, and for the private sector to “strengthen building codes and standards” as a means of fulfilling internal security objectives. Critical infrastructure systems as defined by the President's Critical Infrastructure Assessment Office (CIAO) are systems “whose incapacity or destruction would have a debilitating impact on the defense or economic security of the nation.” The CIAO identifies vital services as: (1) Telecommunications. (2) Electric Power Systems. (3) Gas and Oil. (4) Banking and Finance. (5) Transportation. (6) Water Supply Systems. (7) Government Services and Emergency Systems. (8) Agriculture. (9) National Icons and Monuments. This state‐of‐affairs requires a new breed of codes and standards that compels Standards Development Organizations (SDOs) to undertake what may be their most challenging tasking for their standards development processes and standards. A new class of “Defensive Codes and Standards” (DCS) is required that maximizes reliability and continuity of vital services in extraordinary circumstances, while at the same time attempting to satisfy practicable economic objectives: traditionally, these two objectives have been mutually exclusive. The suppositions used in Defensive Code and Standards (DCS) development include scenarios where whole sections of buildings are suddenly damaged or obliterated through attacks that involve sustained and intense fire and explosion, loss of utilities and communications, loss of fire suppression systems, loss of access and escape routes and prolonged inaccessibility to emergency support services, and the introduction of chemical, biological and nuclear contaminants.

Select this Article		High Impact Shock Testing: Prepared for the American Society of Civil Engineers and the 2006 Architectural Engineering National Conference Regarding Building Integration Solutions Rupert P. Chandler, P.E. ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)65 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Life safety and critical mission equipment used in buildings most always have some dependency on electrical services and equipment (e.g., fire pump controllers, alarming, announcing and monitoring systems, etc.). In typical building construction for electrical equipment and devices, engineering assumptions are that such critical equipment reside in a safe, static environment, absent environmental or man‐made conditions, such as blast and shock that could impact equipment reliability and operations. Therefore, and with little exception, (e.g., seismic, concerns) shock testing and shock performance requirements for such equipment and systems are not common considerations, and there is little in the way of shock guidance to guide engineers in the design‐development of commercial systems as used in buildings. However, dealing with shock and blast issues are a normal part of business when addressing equipment and systems used in marine combatant vessels, and shock testing requirements of shipboard machinery, equipment, and systems may be exportable, with little modification, to building vital systems, while incurring little added expense. This paper describes the testing procedures and methods used to qualify U.S. Navy items as Class A and Class B shock hardened and discusses how such requirements can be made to apply to vital building systems. Many items of furniture, equipment, and critical systems relying on electrical services have been designed, tested and approved per such requirements. Commercial buildings using this technology will be better able to withstand and survive shock loads caused by blast and other environmental factors.

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STRUCTURAL MODELING

Select this Article		Modal Analysis Methods for Validation of Vaulted Stone Masonry Models Thomas E. Boothby, Huriye Sezer Atamturkur, and Linda M. Hanagan ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)66 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Detailed three‐dimensional finite element models are used in the assessment of masonry vaults and domes, in order to determine support reactions and stresses within the vault under various loading conditions. However, it is important to validate the models used on an existing structure by comparison of the results of the analysis to the response of the prototype. The problem of validating a structural model is particularly difficult for large‐scale masonry vaults due to difficulties in access, and difficulties in loading the structure sufficiently to obtain a measurable response. Visual methods, such as investigation of cracks and comparing crack locations to tension zones in the model have been used with limited success; however, the lack of information on boundary conditions makes this method susceptible to error in structures with support settlements. Recently, modal testing has been proposed as a model validation procedure. In this procedure, the dynamic characteristics of the experimental model and the prototype can be compared. These comparisons may be simple comparisons of natural frequencies or much more complex determinations of mode shapes by methods of modal analysis. This paper reviews the application of modal analysis methods to masonry vault validation, and shows some specific examples, including detailed modal analysis tests done on the National Cathedral in Washington, DC, tests done on the Cathedral of St. John the Divine in New York City.

Select this Article		Modal Analyses on the Lateral Resistance System of the Auxerre Cathedral Ece Erdogmus, Ph.D., M.ASCE, AEI Member and Derrick Fitton ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)67 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract One of the unique characteristics of the French Gothic is the use of flying buttresses over the side aisles to support the thrust of the nave vaults. It can also be hypothesized that the medieval master masons must have used these buttresses liberally for lateral resistance against external forces such as high winds. Moreover, there is an increasing interest on the seismic resistance of historical buildings in Europe, which emphasizes further the need to better understand the lateral capacity and dynamic behavior of Gothic structures. In this study, a finite element model of the transverse frame of the Auxerre cathedral in France is developed, and analyzed under lateral loads with and without the flying buttresses to observe the difference in behavior. The dynamic behavior of this finite element model, which is developed with previously validated material properties, is compared to hand‐calculated modal analysis of a simplified frame with multiple beam elements. This is a research in progress with objectives of better understanding the design considerations behind the use of flying buttresses, and developing an accurate and practical method for analyzing the dynamic behavior of Gothic structures.

Select this Article		Experiments and Analyses on a Timbrel Dome Ece Erdogmus, Ph.D., M.ASCE, AEI Member and Brian Skourup ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)68 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract The Nebraska State Capitol in Lincoln contains some of the best examples of timbrel vaults and domes designed by the Spanish architect Rafael Guastavino in the 1930's. In this unique construction style, the thin bricks are placed flatly, forming one or more layers and they are constructed without centering or other support. In the case of a dome, the bricks are placed in concentric rings to complete a semi‐sphere. During the construction, the bricks are supported by the adhesion of the fast‐setting mortar to the completing walls or to the bordering walls. A half scale model of one of these timbrel domes in the Nebraska State Capitol is constructed at the Peter Kiewit Institute Structures Laboratory of the University of Nebraska. The model dome is designed according to Guastavino's original drawings gathered from the Capitol archives, and the construction procedures described in the pertinent literature are followed closely. In this article, first, the details of the construction of the model dome are presented. Then, initial assessments on the structural behavior of the timbrel dome construction will be discussed based on preliminary results of modal experiments and finite element analyses.

Select this Article		The Structural Characterization of Domes of Sinan's Mosques A. I. Unay ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)69 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract Dome is one of the fundamental structural systems used in wide‐span prestige buildings. It is known as a graciously dominant building element and was used for this quality in some edifices constituting the cultural heritage of various civilizations all through history. A meaningful and ingenious usage of the dome had taken place during the sixteenth century of the Ottoman Empire in all the architectural masterpieces erected by the great Turkish master builder Sinan. Extraordinary contribution of Sinan to building art and especially to the development of the dome construction is the major topic of this article.

Select this Article		Field Investigation of the 14th Century Castle Pernstejn before and after Fire Damage Bo Kasal, Michal Kloiber, and Milos Drdacky ASCE Conf. Proc. doi:http://dx.doi.org/10.1061/40798(190)70 Online Publication Date: 20 June 2006 Full Text: \| Download PDF
	+ -	Show Abstract In 2004, timber structures of the 14th century Castle Pernstejn were investigated by non‐destructive methods that included ultrasound, dendrochronology, resistance drilling, and core and tension micro‐specimens. In the spring of 2005, a fire destroyed a corn‐loft of the castle and only horizontal floor beams had remaining load‐bearing capacity. The same sets of in‐situ experiments of the identical members to those tested in 2004 were performed after the fire and the results have been compared to the previous ones.