Fragility curves for steel-concrete hybrid tall buildings

Fragility curves of steel-concrete hybrid tall buildings designed according to the current Chinese seismic design code were derived by analytical methods, taking into account the uncertainty of earthquake ground motions. In total, 45 analytical models were analysed considering all combinations of three design parameters, i.e., seismic protection intensity, site soil type and design group. On the basis of a large number of nonlinear time history analyses, fragility curves were derived reflecting exceeding probabilities corresponding to each performance level. The influence of different engineering demand parameters (EDPs) and design parameters on fragility curves was analysed. The result showed that fragility curves based on different EDPs varied significantly, indicating that different structural components played different roles in seismic performance of the structure. While seismic protection intensity had little impact on seismic vulnerability, structures tended to be more vulnerable on the site with softer site soils and longer characteristic periods.