大跨度斜拉桥地震易损性分析

摒弃传统易损性分析假定，采用增量动力分析方法，提出改进损伤指标参数，对脉冲地震波和非脉冲地震波进行对比，定量分析桥梁结构损伤程度.首先，建立大跨度斜拉桥精细化有限元模型，使用增量动力分析方法，进行大跨度桥梁2 100次非线性时程分析；然后，以斜拉桥桥墩墩底、主塔塔底和支座系统为研究对象，选取合适的损伤指标建立各构件在不同损伤状态下的限值；最后，根据桥梁构件在各级地震作用下的损伤概率，为桥梁抗震提供参考意见.

Research on Vulnerability Analysis Method of Long-span Cable-stayed Bridge Based on IDA

The traditional vulnerability analysis of long-span cable-stayed bridges lacks the comparative analysis of the dynamic response of bridge structures under the action of pulse and non pulse seismic waves; There is a lack of quantitative evaluation of bridge structure damage index in the current seismic design in China. Based on the incremental dynamic analysis method, this paper abandons the traditional vulnerability analysis assumptions, proposes to improve the damage index parameters, compare the pulse seismic wave and non pulse seismic wave, and quantitatively analyze the damage degree of each bridge structure. Firstly, the refined finite element model of long-span cable-stayed bridge is established, and 2100 nonlinear time history analyses of long-span bridge are carried out using incremental dynamic analysis method; Then, taking the bottom of each pier, the bottom of the main tower of the cable-stayed bridge and the support system of the cable-stayed bridge as the research object, appropriate damage indicators are selected to establish the limit values of each component under different damage states; Finally, according to the damage probability of bridge components under various levels of earthquake, suggestions for seismic design under different scenarios are given to provide reference for the concept of bridge seismic design.