Vulnerability Analysis of Main Aftershock Sequence of Aqueduct Based on Incremental Dynamic Analysis Method

Abstract

At present, traditional seismic design methods often ignore the structural damage caused by aftershocks in the evaluation of structural stability. In this paper, seven main aftershock sequences were constructed by using the attenuation method. The incremental dynamic analysis method (IDA) was used to analyze the nonlinear dynamic time history of the aqueduct structure. The main aftershock vulnerability curve of the aqueduct structure was obtained by taking the seismic intensity IM and the maximum ratio of the plastic strain energy to the total strain energy Dp as the structural performance parameter. The analysis results show that the residual displacement of the aqueduct increases by 33%, 66%, 44%, 37%, 0.01%, 60%, and 59%, respectively, under the seven main aftershock sequences. The incremental damage percentages of the aftershock at the end of the period were 9.85%, 15.00%, 26.53%, 2.10%, 0.9%, 35.97%, and 9.85%, respectively. The main aftershock made the damage at the bottom of the arch and the aqueduct more extensive. When the earthquake intensity is 0.3 g, the exceedance probabilities of moderate damage and severe damage are 62.68% and 14.39%, respectively, under the action of the main aftershock sequence. The exceedance probabilities under the action of the main aftershock sequence are 38.52% and 12.08% higher than that of the single main earthquake, respectively.