纵向地震激励下倒Y形主塔斜拉桥的地震易损性分析  

Seismic Fragility Analysis of Upsidedown-Y-Shaped Tower for Long-Span Cable-Stayed Bridges under Longitudinal Excitation

作　　者：焦驰宇[1] 李建中[2] 龙佩恒[1] 

机构地区：[1]北京建筑工程学院"工程结构与新材料"北京高等学校工程研究中心,北京100044 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《石家庄铁道大学学报（自然科学版）》2012年第3期17-23,共7页Journal of Shijiazhuang Tiedao University(Natural Science Edition)

基　　金：建设部研究开发项目(2010-k3-47);北京市优秀人才项目(070900601)

摘　　要：结合我国现役大跨斜拉桥的结构特点,以III类场地上的倒Y型主塔斜拉桥为研究对象,选取20条实测地震波进行增量动力分析,同时将材料应变计算的截面曲率水平作为斜拉桥塔、墩、桩的损伤指标,据此求解斜拉桥塔、墩、基础等构件在不同地震动水平下超越不同损伤状态的概率,然后利用非线性拟合获得倒Y形主塔斜拉桥各构件地震易损性曲线,获得斜拉桥地震易损部位,损伤破坏过程的认识。研究表明:从各构件损伤的超越概率由高到低的排序上看,斜拉桥的主塔是最不易损的构件,而过渡墩桩基是最易损伤的构件;Y形主塔的易损部位主要集中在下塔底、中塔底、中塔顶三个部位。The sample of cable-stayed bridge studied in this paper is based on the structural characteristics of cable-stayed bridges recently built in China. Excited by twenty ground motion waves belonging to III soil site type, the incremental dynamic analysis of cable-stayed bridge is made herein. The probabilities of different dam- age state exceedance of the main tower are studied, as well as the transition pier, auxiliary pier and the piles subjected to different ground motion level. To compare the seismic vulnerability of different components, the seismic fragility curves for different components of the sample cable-stayed bridge are developed. The research show ： for upsidedown-Y-shape tower of the cable-stayed bridge, the vulnerable zones appear often on three posi- tions, which are tower bottom, middle tower bottom, and top of the middle tower.

关 键 词：斜拉桥 地震易损性 增量动力分析 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]