基于耐震时程法的拱坝-地基系统易损性分析

Vulnerability Analysis of Arch Dam Foundation System Based on ETA Method

为研究高拱坝-地基系统在强地震动作用下的易损性,本文以白鹤滩拱坝为研究对象,采用耐震时程法(endurance time analysis,ETA)生成人工地震动时程进行动力时程分析.选取最大横缝开度、损伤体积比和顺河向相对位移为指标.分别选取典型破坏状态作为结构破坏标准,基于回归曲线方法、矩估计、多样条分析法和截断最大似然估计等方法获取结构的易损性曲线,探究拱坝结构在不同峰值加速度(peak ground acceleration,PGA)水平下的失效概率,从而从概率角度给出了拱坝-地基系统在不同地震动强度下的破坏状态.从分析原理和实际计算结果出发,矩估计和多样条分析法更适合与ETA法相结合来分析拱坝结构的易损性.

To study the vulnerability of the high arch dam foundation system under strong seismic action,this paper takes the Baihetan arch dam as the research object,and uses the earthquake endurance time analysis(ETA)method to generate artificial seismic motion time history for dynamic time history analysis.Select the maximum transverse seam opening,damage volume ratio,and relative displacement as indicators.Select typical failure states as structural failure criteria,and obtain the vulnerability curves of the structure based on regression curve method,moment estimation,multiple strip analysis method,and truncated maximum likelihood estimation methods.This explores the failure probability of the arch dam structure at different peak ground acceleration(PGA)levels,and provides the failure states of the arch dam foundation system under different seismic intensity from a probability perspective.Starting from the analysis principles and actual calculation results,the moment estimation and multiple strip analysis methods are more suitable for combining with the ETA method to analyze the vulnerability of arch dam structures.