基于分布调幅法的钢框架结构主余震易损性分析

Vulnerability analysis of mainshock-aftershocks of steel frame structure based on distributed amplitude modulation method

传统主余震易损性分析仅将主震及单一余震强度作为地震动输入,并只采用易损性曲线来评估结构的安全性能,这会导致结构进行主余震易损性分析时存在一定的局限性。针对上述问题,采用分布调幅法按不同余震幅值比对余震进行调幅处理,对结构进行不同余震强度下的主余震易损性分析。此外,基于主余震极限状态概率曲线与破坏状态概率曲线,计算不同余震强度下的主余震易损性指数,从易损性指数及易损性曲线两个角度,研究不同余震强度对结构的影响。研究表明,考虑不同余震强度下结构的失效概率使得主余震易损性曲线结果更加详细;主震在定义结构破坏状态中虽然起到主导作用,但是余震强度的变化有可能会造成结构破坏状态的跃迁;从易损性曲线及易损性指数两个角度,可以使结构进行主余震易损性分析时更加全面完整。

The traditional mainshock-aftershock vulnerability analysis only takes the main shock and single aftershock intensities as the ground motion input,and only the vulnerability curve is used to evaluate the safety performance of the structure,which leads to certain limitations in the vulnerability analysis of the mainshock-aftershock.Aiming at the above problems,this paper adopts the distributed amplitude modulation method to deal with the amplitude modulation of aftershocks according to different aftershock amplitude ratios and analyzes the vulnerability of the mainshock-aftershock to the structure under different aftershock intensities.In addition,according to the main aftershock limit state probability curve and the failure state probability curve,the mainshock-aftershock vulnerabilityindexbelowthe different aftershock intensities is calculated,and the influence of different aftershock intensities on the structure is studied from the perspective of vulnerability index and vulnerability curve.The study shows that the intensities makes the results of the mainshock-aftershock vulnerability curve more detailed based on the failure probability of the structure under different aftershock;although the main shock plays a leading role in defining the failure state of the structure,the change of the aftershock intensity may cause the failure state of the structure transition;the vulnerability analysis of mainshock-aftershock of the structure can be more comprehensive and completefrom the perspectives of vulnerability curve and vulnerability index.