Fragility analysis of reticulated domes subjected to multiple earthquakes.

• Different with the traditional method that structural seismic responses were directly compared, in this study, through seismic fragility analysis, we investigated the aftershock influence on seismic performance of reticulated domes from probability perspective. • Existing researches have proved that the dominant vibration mode-based ground motion intensity measure S a , dom (Td 1 , Td 2 , ..., Td i , ..., Td N , ξ) was proposed as the most appropriate ground motion intensity measure for reticulated domes. However, it is not suitable for seismic study subjected to aftershocks, because the dominant vibration modes of damaged reticulated domes under main shocks would change. Therefore, in this study, we proposed the appropriate aftershock ground motion intensity measure for reticulated domes. • Based on the above ground motion intensity measure, we performed the fragility analysis of intact reticulated domes under main shock-aftershock sequences, and obtained the main shock-aftershock sequence fragility curves of structures for seismic design of reticulated domes considering multiple earthquake effects before earthquakes. • Different with the traditional seismic fragility analysis, we also performed the fragility analysis of damaged reticulated domes with different damage levels caused, which lead seismic fragility analysis not limited to intact structures and expanded the application scope of seismic fragility analysis. 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. [ABSTRACT FROM AUTHOR]