Seismic Risk Assessment of Reinforced Concrete Building Using Fema P-58 Methodology

Abstract

Among natural hazards, earthquakes represent the largest potential source of damage. Observations from past earthquake events indicate that they result in significant losses, both social and financial. As those losses are function of buildings damage, a well-recognized seismic assessment of building performance can help mitigate the effects of devastating earthquakes. The prediction of a building's seismic loss is crucial to its resilience, yet the evaluation process is quite complex. FEMA P 58 is a tool in which a comprehensive procedure is formulated to assess the seismic performance of a building. This tool provides detailed building risk information, such as which components are most likely to be damaged and if applicable, how long it will take to rebuild. This study focuses on the seismic performance evaluation of an 8-story reinforced concrete building implementing the FEMA P-58 methodology. The building is considered to have symmetrical configuration and for study purposes it is supposed to be located in Portland, USA. The frame elements are characterized by same material properties: the concrete compressive strength is approximately 34.5 MPa and the steel tensile strength is approximately 413.6 MPa. Given the FEMA P 58 facilities, specific fragility groups are first selected. Next, building performance is evaluated following the intensity-based assessment approach. Finally, expected annual losses for the building studied are derived and presented in graphical form. iii My research findings indicate that any building detail influences the results of the earthquake consequence. Following the Monte Carlo approach for 500 realizations, the outcome of this study produces a summary of performance group’s impact to the overall cost. The results show that the residual drift plays a significant role to the total repair cost, which for approximately 25 of the 500 realizations is judged irreparable. For earthquake intensity used, no collapse occurs, and the post-tensioned flat slabs are predicted to be the primary contributor to repair costs. The integration of FEMA P-58 methodology with structural analysis in SAP2000, give loss prediction results, which can be used to assess the post-earthquake costs of various structures.