基于IDA方法的山地吊脚框架结构地震易损性分析

Seismic Vulnerability Analysis of Mountain Stilted Frame Structure based on IDA Method

本文采用Midas Building软件按规范设计不同结构的吊脚模型,并对每一个吊脚结构模型用增量动力分析法进行易损性研究。每个模型分别选取20条地震动记录进行结构时程分析,建立结构IDA曲线,确定结构各极限破坏状态点,得到不同极限状态下的地震易损性曲线,分析结构的层数和跨数对吊脚框架结构地震易损性的影响。结果表明:层数的增加使吊脚结构的离散性减小,且在结构破坏状态和损伤指标相同的情况下,地震动强度随层数的增加而增大;地震动强度相同时,结构在破坏状态下的超越概率随着层数的增加而减小,而跨数的增加对吊脚结构在地震作用下易损性的影响不明显。

In the paper,Midas Building software is used to design different structural foot models according to specifications,and each foot structural model is studied by incremental dynamic analysis.Twenty ground motion records were selected for structural time-history analysis in each model,and the IDA curve of the structure was established to determine the limit failure state points of the structure,and the seismic vulnerability curves under different limit states were obtained.The influence of the number of layers and spans of the structure on the seismic vulnerability of the suspended foot frame structure was analyzed.The results show that the increase of the number of layers reduces the dispersion of the foot structure,and the seismic intensity increases with the increase of the number of layers under the same structural failure state and damage index.When the ground motion intensity is the same,the exceedance probability of the structure in the failure state increases with the increase of the number of layers,while the increase of span has no obvious effect on the vulnerability of the foot structure under earthquake.