Vulnerability Analysis of Typical Six-story RC Frame Structure under Mainshock-aftershock Ground Motions

In order to study the vulnerability of the RC frame structure under the influence of mainshock-aftershocks, a typical six-story RC frame structure is taken as an example. Incremental dynamic analysis and vulnerability analysis are used to compare and analyze the transcendental probability of the RC frame structure under different performance states and various mainshock-aftershocks effects.10 seismic records have been selected as the seismic input based on site conditions. The response spectrum acceleration is used as the intensity measure（IM）, while the maximum interlayer displacement angle is used as the damage measure（DM）. The IDA curve cluster is analyzed by quantization, and a probabilistic seismic demand model is established using the seismic intensity measure. The vulnerability analysis of the frame structure is performed according to the defined structural performance level.The results show that the bidirectional earthquake and the main-aftershocks increase the vulnerability index of the structure com