EFFECT OF EPISTEMIC UNCERTAINTY ON SEISMIC FRAGILITY OF BASE-ISOLATED RC-BUILDING FRAME USING INCREMENTAL DYNAMIC ANALYSIS

Abstract

The quantification and impact of epistemic uncertainty in the RC frame building can analyze due to recent advancements in processing power and the availability of reliable seismic vulnerability assessment techniques. In the present study, a base-isolated 10-story RC building frame is designed and analyzed per the latest Indian standards, with lead rubber bearing as the base isolation system. The selected base-isolated RC frame building was analyzed using probabilistic and deterministic approaches. As the fundamental epistemic uncertainty parameter, the mechanical strength of concrete and steel is considered. The Monte-Carlo method is determined the unpredictability of the RC frames' structures. The incremental dynamic analysis is conducted per the FEMA P695 guidelines to evaluate the wide range of 32 far-field ground motions on the base-isolated RC frame structure. Maximum roof drift ratio responses are utilized to generate the seismic fragility curve by adopting the several threshold values of damage index, such as, slight, moderate, severe, and complete. The traditional linear regression method is implemented to derive the seismic fragility curves of various damage thresholds. The study results reveal that the deterministic strategy is more likely to predict damage by 10 to 25 percent less than the probabilistic approach. The probabilistic analysis approach shows that epistemic uncertainty significantly affects the prediction of the seismic damage probability