Seismic risk analysis of multistory reinforced concrete structures in Saudi Arabia

In this research, analytical fragility curves for typical mid-rise plane reinforced concrete moment-resisting frames in Kingdom of Saudi Arabia, KSA, which is considered low-seismicity area, are presented. The fragility curves are developed for 12-story reinforced concrete structure designed according to Saudi Building Code under dead, live and seismic loads. Three cities with different seismic intensities; Abha, Jazan and Al-Sharaf were selected to cover various values of mapped spectral accelerations in KSA. The 0.2-second spectral accelerations range from 0.21 g to 0.66 g while the 1.0-second spectral accelerations range from 0.061 g to 0.23 g. Incremental Dynamic Analysis, IDA, was performed under twelve ground motions using SeismoStruct. Five performance levels; Operational, Immediate Occupancy, Damage Control, Life Safety and Collapse Prevention, which define different possible damage states of a building after an earthquake, were considered and monitored in the analysis. Based on the results of the IDA and statistical analysis, the probability of reaching or exceeding a specific damage state was calculated for each structural model in the three cities. The results were fitted and the fragility curves were developed and presented.