地震作用下城市轨道交通桥梁-轨道系统关键部件易损性分析  

Fragility Analyses of the Key Components in the Urban Rail Transit Bridge-rail System Under Seismic Conditions

作　　者：葛新宇 张吉 田石柱[1,2] GE Xinyu;ZHANG Ji;TIAN Shizhu(Suzhou University of Science and Technology,Suzhou 215009,China;Jiangsu Key Laboratory of Structural Engineering,Suzhou 215009,China)

机构地区：[1]苏州科技大学,江苏苏州215009 [2]江苏省结构工程重点实验室,江苏苏州215009

出　　处：《铁道标准设计》2024年第7期118-124,131,共8页Railway Standard Design

基　　金：江苏省基础研究计划(自然科学基金)青年基金项目(BK20200990);江苏省高等学校自然科学研究基金项目(20KJB580001)。

摘　　要：为对地震作用下城市轨道交通桥梁-轨道系统关键部件损伤状态进行分析,以上海城市轨道交通11号线高架段为研究对象,通过OpenSees建立梁轨一体化抗震分析模型。选取符合目标反应谱的10条地震波进行调幅,将调幅后的地震波输入抗震分析模型中;选取桥梁支座、钢轨以及轨道扣件作为轨桥系统关键部件,进行增量动力分析(incremental dynamic analysis,IDA)并提取对应的IDA曲线,对IDA曲线进行回归分析得到支座与扣件地震概率需求模型数学表达式;提出支座、钢轨以及轨道扣件损伤状态界限值,基于正态分布假设得到支座与扣件不同损伤状态下超越概率,据此绘制易损性曲线。结果表明,罕遇地震作用下钢轨横向残余变形较小,发生轻度损伤概率为0%;当峰值加速度超过0.5g时,支座发生轻度损伤超越概率显著增加,扣件发生轻度损伤的超越概率接近100%;选取不同损伤指标对扣件进行易损性分析时,以位移幅值为损伤指标得到的扣件损伤概率更高;随着地面峰值加速度的增大,扣件有较大概率先于支座发生损伤。In order to analyze the damage status of key components of urban rail transit bridge-rail system under seismic conditions,the track-bridge system of Shanghai Urban Rail Transit Line 11 is selected and analyzed in this study.Numerical model of the coupled track-bridge system is established in OpenSees for seismic analyses.10 ground motion records which conform to the target response spectrum are selected and scaled.These records are then input into the seismic analysis model.Bridge bearings,rails and rail fasteners are selected as key components of the rail bridge system for incremental dynamic analysis(IDA)and the corresponding IDA curves are extracted.The mathematical expression of the seismic probability demand model is developed by regression analyses for the bearing and the fastener respectively.The damage states and the corresponding limit states are proposed for the bearings,rails and fasteners.For both the bearing and the fastener,the probability of exceedance under each damage state is obtained based on the normal distribution assumption,and the fragility curve is obtained accordingly.The results show that the lateral residual deformation of the rail is small under the action of rare earthquakes,and the probability of mild damage is 0%.When the peak acceleration exceeds 0.5g,the probability of exceeding mild damage for the bearing increases significantly,and the probability of exceeding mild damage for the fastener approaches 100%.Two different damage indicators are adopted for the fragility analysis of the fastener.When taking the displacement amplitude as the damage index,the damage probability of the fastener is higher.With the increase of the peak ground acceleration,there exists a large probability that the fastener exhibits damage prior to the bearing.

关 键 词：城市轨道交通 桥梁-轨道系统 支座 钢轨 扣件 增量动力分析 易损性分析 

分 类 号：U231[交通运输工程—道路与铁道工程] U211.9[建筑科学—桥梁与隧道工程] U442.5