Linking Next-Generation Performance-Based Seismic Design Criteria to Environmental Performance (ATC-86 and ATC-58)

Frame structures with exterior verandahs, which are mostly built in densely populated areas such as teaching buildings and dormitories in southern China, are a special form of frame structure that must continue to be developed. However, compared with other frame structures in many post-earthquake fields, this type of building designed following the Chinese code has demonstrated poor seismic performance, leading to a significant number of casualties and property losses. Therefore, to complement the design requirements of this structural type in the present Chinese code, the seismic performance of this structural type needs to be improved and optimized. A typical double-span RC frame structure with an exterior verandah in the Lushan Earthquake as the structure prototype was selected in this paper. PKPM software is used to obtain design information for the structure prototype, and the finite element model is established by utilizing ABAQUS software for simulation and analysis. A series of various optimal conditions are created at the base of the structure prototype’s simulation results, and a thorough investigation of the structural seismic performance under each condition is performed. Eventually, suggestions and proposals for future Chinese codes concerning the structurally optimum design of this structural type are provided.

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Numerical Study on Optimal Design and Seismic Capacity of Double-Span RC Frame Structures with Exterior Verandahs

Research on a methodology for intelligent seismic performance evaluation and optimization design of buildings based on IFC and ontology

Reinforced concrete (RC) frame-core tube buildings are widely constructed both in China and the United States (US). Their seismic performances greatly influence the economic loss of earthquakes. This study aims to compare the seismic losses of two typical RC frame-core tube tall buildings designed following the Chinese and the US seismic design codes. The prototype building is originally designed using the US seismic design codes, provided by the Tall Building Initiative (TBI) Project. Then the prototype building is redesigned according to the Chinese seismic design codes with the same design conditions and seismic hazard level. Detailed nonlinear finite element (FE) models are established for both designs. These models are used to evaluate their seismic responses at different earthquake intensities, including the service level earthquake (SLE), the design based earthquake (DBE) and the maximum considered earthquake (MCE). In addition, the collapse fragility functions of these two buildings are established using the incremental dynamic analysis (IDA). Subsequently, the seismic loss consequences (repair costs, repair workload, and casualties) of these two designs are calculated using the procedure proposed by FEMA P-58. The comparison shows that the Chinese design exhibits better seismic performances in most cases with smaller total repair cost, shorter repair time and a smaller number of casualties, except slightly longer repair time at the MCE level. For both designs, the repair cost of nonstructural components accounts for the majority of the total cost. The ceilings and elevators are the major causes of casualties at the MCE level.

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Seismic loss assessment of typical RC frame-core tube tall buildings in China and US using the FEMA P-58 procedure

In 2001, the Applied Technology Council (ATC) initiated the ATC-58 Project under contract to the Federal Emergency Management Agency (FEMA). Under this project, ATC is developing next-generation performance-based seismic design criteria for new and existing buildings that will be published as FEMA P-58. Unlike present-generation performance-based design criteria, which characterize structural and nonstructural performance in terms of standardized damage states, the P-58 criteria characterize structural performance in terms of the consequences of earthquake damage including: casualties; repair and reconstruction costs, expressed both in monetary and energy/carbon expenditures; and occupancy interruption time. The performance of nonstructural building components including architectural, electrical and mechanical components and systems is integrally considered with that of the structure. Following a methodology originally developed by the Pacific Earthquake Engineering Research Center, the P-58 procedures revolve around a building performance model that includes fragility and consequence functions for each of the damageable components and systems of significance. Monte Carlo simulation procedures are used to assess potential losses for: individual earthquake shaking intensities; scenario earthquake events, considering uncertainty in ground motion intensity; and, over a period of time, considering uncertainty in the magnitude and distances of scenario events that will occur. Project completion is scheduled for late 2011.

Ronald O. Hamburger

Papers

FEMA P-58-Next-Generation Performance Assessment of Buildings