Evaluation of seismic resilience of RC-building subjected to repeated earthquake using resilient index and fragility surface functions

Abstract

Seismic resilience is a modern approach that aims to return the community of damage to its natural condition in a shortest possible time. Seismic resilience could be interpreted as a structure's ability to maintain a degree of functionality over a particular period of time once it is exposed to seismic events. The research study aims to address with an approach of functionality and seismic resilience of a mid-rise Ordinary Moment Resisting Frame (OMRF) structure subjected to repeated earthquakes. Besides, as a vulnerability and functionality study for risk assessments, both the Seismic Resilience Index (SRI) and the fragility surface were used to determine the seismic resilience of the selected building. The fragility surfaces expressed the probability of damages with respect to intensity measure and seismic event period (T). The concept phases of this approach were as follows: (1): Select targeted buildings, (2): Select and scaled a set of repeated Seismic Ground Motion (SGM) records, (3): Generate an Incremental Dynamic Analysis (IDA), (4): Fragility surface and (5): Functionality curve, with seismic resilience index (RI). Eventually, after investigating the structure through the vulnerability assessment, initiating with IDA, and ending with the fragility surface, it is clearly established that the buildings do not have the capacity to withstand a 15 sec repetitive earthquake due to their ordinary structural design related to ductility demand. Meanwhile, with an increase in the possible seismic ground acceleration, the fluctuation in functionality, SRI, robustness, structural losses, and time recovery of distinct performance levels could be estimated.