Fragility Analysis of Base Isolated Building

This book presents a probabilistic seismic risk assessment of friction pendulum base-isolated buildings under far fault and near-fault earthquakes by conducting fragility analysis. For this purpose a ten-storey RC frame base-isolated with friction pendulum bearing is considered for the study. Fragility curves were developed for the far-field and near field including directivity and fling step effect earthquakes for the various damage measures like maximum interstorey drift ratio (MDR) maximum roof drift ratio (MRDR) maximum base shear (MBS) maximum top floor acceleration (MTA) and maximum isolator displacement (MID). The incremental dynamic analysis was carried out for fragility curves by assuming different limit states like slight moderate extensive and collapse. The results show that even under low PGA level the near field earthquakes with having high PGV to PGA ratio and fling step effect cause a high probability of exceedance for friction pendulum bearing. The PGV: PGA ratio had a greater damage probability than the low PGV: PGA ratio.