Research On Seismic Vulnerability Of RC Frame Structure Based On Incremental Dynamic Analysis

Most of the earthquake disaster results show that the damage caused by the structure under the near-field earthquake is more serious.In this paper,based on the incremental dynamic analysis method?IDA?,the seismic vulnerability of structures to different performance states under near-field earthquakes is studied..?1?Using ABAQUS software to establish an RC framework structure,and perform modal analysis to provide calculation basis for IDA analysis of structure.According to the ATC-63wave selection principle to select 54 near-field seismic waves,and the seismic waves were amplitude-modulated and analyzed by IDA.From the plotted vulnerability curve and the calculated safety reserve coefficient?CMR?,the RC structure can easily reach the normal use stage of the structure under the action of small earthquakes,under the action of large earthquakes,the structure has a small probability of overshoot,and the structure is not easy to collapse;the structure design meets the seismic requirements specified by the design code.?2?The spectral acceleration S_a?T₁?and the peak velocity PGV are selected as the ground motion intensity parameters to analyze the structure.,and use Matlab software to draw the vulnerable surface composed of S_a?T₁?and PGV.The results show that the structural surpass probability with S_a?T₁?And PGV increases continuously and increases;but as the degree of structural damage increases,the influence of PGV on S_a?T₁?on structure is more obvious.?3?The influence of different concrete strength and distance fault size on the seismic performance of the frame structure,compared with the vulnerable surface and the collapse safety reserve coefficient?CMR?,the analysis results show that the influence of concrete strength on the collapse resistance of the structure is not obvious under the action of small earthquakes;the collapse resistance of the structure under the action of large earthquakes increases with the increase of concrete strength,the probability of structural overshoot decreases,and the possibility of collapse becomes smaller.As the distance of the seismic wave distance from the fault decreases,the probability of the near-field vibration exceeds the probability of the far-field vibration,and the CMR of the far-field vibration is greater than the CMR of the near-field vibration;the vulnerability surface and the calculation result show that Under the same S_a?T₁?and PGV,the impact of near-field vibration on the structure is more obvious than that of far-field vibration.