大跨度轨道交通桥梁抗震性能分析  

Analysis of Seismic Performance of Long Span Rail Transit Bridge

作　　者：施颖[1] 宣纪明 姚君[1] 张振宇[1] 

机构地区：[1]浙江工业大学建筑工程学院,浙江杭州310014 [2]浙江工业大学工程设计集团有限公司,浙江杭州310014

出　　处：《桥梁建设》2017年第6期42-47,共6页Bridge Construction

摘　　要：为了解轨道约束作用和摩擦摆支座对轨道交通桥梁抗震性能的影响,以某大跨轨道交通桥梁[(85+135+85)m预应力混凝土连续梁]为背景,采用MIDAS Civil软件建立考虑轨道约束作用的线桥一体化有限元模型,选取承受惯性力最大的固定墩作为研究对象,研究轨道约束作用对桥梁抗震性能的影响和摩擦摆支座的减隔震效果,分析墩高对摩擦摆支座减隔震效果的影响。结果表明:考虑轨道约束作用后,桥梁的纵向自振频率有所提高,横向自振频率变化很小;考虑轨道约束作用时,固定墩的墩顶位移、墩底弯矩和墩底剪力比不考虑轨道约束作用时均明显增大;采用摩擦摆支座能显著降低固定墩的地震响应,摩擦摆支座具有良好的减隔震性能;摩擦摆支座的隔震效果随墩身高度的增加逐渐减小,摩擦摆支座适合在桥梁固定墩墩身刚度较大时采用。To understand the influences of the track constraint and friction pendulum bearingson the seism ic perform ance of the rail transit bridge, a long span bridge of the sam e kind [th e maingirder of the bridge being the prestressed concrete continuous girder w ith span arrangem ent （85 ＋135 ＋ 85） m ] w as taken as an exam ple and the softw are M IDAS Civil w as used to establish thetrack and bridge integration finite elem ent model considering the track constraint. T he fixed pier ofthe bridge subjected to the greatest inertial force w as selected as the research object, the influencesof the track constraint on the seism ic perform ance of the bridge and the seism ic m itigation and isolationeffects of the friction pendulum bearings w ere studied and the influences of the pier height onthe seism ic m itigation and isolation effects w ere also analyzed. T he results indicate that after thetrack constraint is considered, the longitudinal natural vibration frequencies of the bridge increaseto some extent while the transverse natural vibration frequencies do not change greatly. W hen thetrack constraint is considered, the fixed pier top displacem ent, footing bending m om ent and footingshear increases significantly as com pared to the case w hen the track constraint is not considered.T he utilization of the friction pendulum bearings can significantly decrease the seismic responsesof the fixed pier and the bearings have good seism ic m itigation and isolation perform ance.W ith the increase of the pier height, the seism ic m itigation and isolation effects of the bearingsgradually decrease and the bearings are applicable w hen the rigidity of the fixed pier of the bridge is great.

关 键 词：轨道交通桥梁 抗震性能 固定墩 轨道约束作用 摩擦摆支座 有限元法 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]