Fragility analysis of reticulated domes subjected to multiple earthquakes

In this paper, single-layer and double-layer reticulated domes were taken as two typical research objects. Through the dynamic time history analysis of reticulated domes in full process domain, log-linear regression was performed with a large number of example results to compare the degrees of correlation and efficiency about 11 common ground motion intensity measures, and PGA was selected as the most applicable one for fragility analysis of reticulated domes with aftershock influence. Then, considering that main shock usually caused structural damage, with incremental dynamic analysis method, fragility analysis of reticulated domes under multiple earthquakes was conducted from two aspects as follows. One part was main shock-aftershock sequence fragility analysis of intact structures. The other part was aftershock fragility analysis of damaged structures with four different damage levels caused by main shocks. Based on the fragility curves, the aftershock influence on fragility of reticulated domes and the aftershock collapse probability of damaged reticulated domes with four different damage levels caused by main shocks were investigated. It was found that when the damage level reached severe damage under main shocks, the aftershock collapse probability of reticulated domes would increase significantly. The results expanded the application scope of traditional fragility analysis in seismic engineering and realized the prediction and evaluation of seismic performance of reticulated domes under aftershocks.