Journal of Architectural Engineering

Structural insulated panel (SIP) wall systems have been used in residential and light commercial buildings for the past 60 years. Lack of sufficient published research results on racking load performance and understanding of the influence of fastener types on seismic response has been a deterrent in the widespread use of the wall system in seismically active areas. This paper summarizes the results of a full-scale racking load testing study in which a total of $\mathrm{17\; 2.4}\times \mathrm{2.4-m} (8\times \mathrm{8-ft})$ SIP wall panels were tested under monotonic and cyclic loading. Four 114-mm (4.5-in.) thick SIP specimens were tested under monotonic loading, while 13 114-mm (4.5-in.) thick SIP specimens were tested under the Consortium of Universities for Research in Earthquake Engineering loading protocol. Parameters such as fastener type, spline design, hold-down anchor location, and sheathing bearing were adjusted throughout the testing to determine their effects on the SIP’s performance. Performance parameters such as peak load and displacement and allowable drift load capacity were determined for all of the SIP specimens. The paper describes the mode of failure for typical specimens under both monotonic and cyclic loading and presents load-displacement data for the tested specimens. The study showed that the fastener type (screw, staple, or nail) was the parameter that had the greatest effect on the performance of the specimen. The SIP specimens that used 8d common nails to connect the framing to the sheathing are shown to be the most effective SIP design in terms of load capacity and resistance under repeated cyclic loading.

The behavior of cable net facades subjected to blast loads differs significantly from the behavior of stiffer structures, such as post-and-rail facades or classical concrete or steel structures. The low eigenfrequencies and the relatively small specific weight of cable net facades cause larger deformations and higher structural velocities. The negative pressure phase of a blast load can especially have a significant effect on the structural response. The negative phase can either increase or decrease the deflections. Nevertheless, the United States and international threat levels according to the United States General Services Administration and the ISO neglect the negative phase of blast loads. In the present investigation, a comparison and assessment was done to present the differences between the standard blast load model, that is, a triangular-shaped blast load neglecting the negative phase, and the exponentially decaying Friedlander blast load model, which takes the negative phase into account. Then, the implications for the structural response are analyzed, and conclusions for the protective design of cable net facades are presented.

A simple method is presented for determining the peak horizontal acceleration of nonstructural components attached to the floor system of multistory structures subjected to strong ground motions. The procedure was developed for nonstructural components based on shake-table data measured on the floor diaphragms of 30 small-scale reinforced concrete test structures. The observed response led to a general expression that directly accounts for the level of inelastic response of the structures. Floor acceleration data from existing instrumented buildings during strong seismic events were used to test the validity of the method. The method was also assessed analytically using acceleration data calculated after nonlinear dynamic analyses of 6- and 12-story reinforced concrete frames subjected to a suite of 10 ground motions scaled to three intensity levels to cause varied degrees of inelastic response in the frame elements. These analyses allowed the inclusion of flexible nonstructural components in the assessment. The formulation involved may be easily incorporated into the framework of modern seismic design provisions for nonstructural components. It is shown that the proposed method outperforms the one in modern model building codes.

A new type of wall system for use in light-frame construction has recently been developed at Penn State University to allow for maximum daylighting and the use of glazing integrated photovoltaics to generate electricity. One structural option of the proposed wall system employs structural steel tubing to form the gravity load-bearing frame and polycarbonate sheets to perform the sheathing function. The exterior skin of the wall consists of a glazing system, which includes aluminum framing and glass panes that incorporate photovoltaics. Preliminary structural tests are presented to show the gravity load carrying capacity of the steel framing and in-plane lateral load carrying capacity of the polycarbonate sheathing. Similar tests were also carried out on conventional wood-frame panels to serve as benchmarks for evaluation of the proposed system. This paper mainly focuses on the structural system and provides a summary of the structural test results, which show that the proposed system can provide gravity and lateral load resistance. The results of this investigation also identify the need for follow-up studies to optimize the proposed design for cost effectiveness and increased thermal insulation.

The ancient methodology of trial-and-error has come a long way over the past hundreds of years, as the construction industry continues to pursue tools that improve design before construction commences. Merging BIM with SmartCodes is a vital step in that evolution. SmartCodes is a new initiative of the International Code Council (ICC) that seeks to automate code compliance check, which takes the building plan as represented by a BIM model and instantly checks for code compliance via model-checking software. The goal is to be able to create a review checklist of building elements to look for, and to inspect the building components that do not comply with code provisions to determine why they do not comply. The introduction of SmartCodes will greatly enhance the traditional design practice by simplifying the access to code provisions and complaints checks. Converting Code and Standards from a flat, rigid format into a dynamic, computable format plays a key role in this process. By breaking through the boundaries of Code and Standard provisions, design software, and Building Information Modeling, a solution to these challenging hurdles can be achieved. This research investigates automated code compliance verification systems that assess building designs according to various criteria, which includes evaluating and examining the functional capabilities of both the technology and structure of SmartCodes and recent code rule checking systems. The paper suggests a new framework for the development of automated code-checking systems that will validate building designs against regulations, provisions, and user-defined conditions.

In this paper, a new scheme is proposed for retrofitting RC buildings to resist progressive collapse that may result from a first floor column failure. The proposed scheme is comprised of placing vertical cables connected at the ends of beams and hung on a hat steel braced frame seated on top of the building. In case of a column collapse, the cables transfer the residual loads above the failed column to the hat-braced frame, which, in turn, redistributes these loads to the adjacent columns. A finite-element modeling and a nonlinear dynamic analysis following the alternate path method (APM), as recommended by U.S. General Services Administration guidelines, are used to assess the viability of the proposed scheme. A 10-story RC building designed according to Australian Standard AS 3600 was adopted in the investigations. The investigation results demonstrate the possibility of preventing the progressive collapse of RC buildings by implementing the proposed scheme.

An in-depth structural analysis is used to explore the design and functionality of the Great Hall of Trajan’s Markets (110 CE), a large Imperial monument cross vaulted in unreinforced Roman concrete. Following a combined approach, the analysis utilizes both field quantities and aggregate equilibrium quantities to determine how the load paths of the structure are utilized to support its own weight. The lateral arch is found not to provide any appreciable buttressing to the vault. Instead, the lower shear wall counters the vault thrusts after they traverse a frictional interface between the two travertine blocks of the support pier. Several facets of the design are altered in hypothetical models to reduce mechanical stresses. An improved configuration mimics later Imperial structures by lowering the lateral arch to the springing level, the horizontal displacement of which is found to directly determine tensile stress magnitudes in the vault. Comparisons with later, larger-span Imperial monuments vaulted in concrete reveal the Great Hall as a significant milestone in the evolution of Roman structural design.

A failed or failing roof system represents a heightened opportunity for failure in the building envelope and inherently increases the risk of additional costs. A leaking roof system also imposes costs on building occupants. Present roof asset management practice typically ignores user or occupant costs in making replacement decisions, basing roof management decisions on fixed intervals, inspection results, maintenance issues, and, occasionally, failure risk. This paper presents a process for valuating occupant costs with respect to roof system failures and then considers the impact of those costs in the roof management decision process. Feedback from occupants at Carnegie Mellon University regarding the impact of approximately 1,800 reported roof leaks over a period of 9 years was used to estimate occupant cost model parameters. Results found that the occupant costs coping with leaks exceed roof maintenance and repair costs in a typical year but are smaller than the average annual roof replacement costs.