考虑碰撞效应的双柱式高墩桥梁非线性地震反应特性研究  

Nonlinear Seismic Response Characteristics of Bridge with Double-column High-rise Piers Considering Pounding Effect

作　　者：高玉峰[1] 蒲黔辉[1] 李晓斌[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《公路交通科技》2011年第4期36-45,共10页Journal of Highway and Transportation Research and Development

基　　金：抗震工程技术四川省重点实验室(西南交通大学)开放基金资助项目(SKZ200907)

摘　　要：以西南山区线路中常用的双柱式高墩桥梁为研究对象,建立典型桥跨结构的空间动力分析模型,采用非线性动力时程分析方法,详细研究了考虑地震碰撞效应时桥梁结构的地震响应特性,并探讨了接触单元刚度取值、间隙宽度、桥台刚度以及支座滑动性能等非线性边界条件的影响。结果表明:梁间碰撞作用主要发生在近桥台伸缩缝处,碰撞作用减小桥墩的地震响应,同时在梁体中产生较大的短时加速度脉冲效应;考虑桥台的纵向约束作用将使得梁间碰撞效应增强;对于通常设计采用的间隙宽度范围,强震作用时碰撞现象会不可避免地发生;支座滑动性能对桥墩的地震响应起到隔震的作用,考虑支座滑动性能后梁间碰撞次数减少;各种非线性边界条件因素的综合作用使得桥跨结构的地震响应变得较为复杂,为获得结构真实响应结果应该合理考虑这些因素的影响。Based on the double-column highway bridges with high-rise piers in southwest mountain area,the spatial dynamic analysis models of representative bridge span were established.The seismic response characteristics of the bridge considering the pounding effect were studied in detail by using nonlinear dynamic time history analysis method.The influence of some nonlinear boundary conditions,including value of contact element stiffness,gap width,abutment stiffness and sliding performance of bearings,were discussed.The results indicate that（1） the seismic pounding effect between adjacent beams occurs mainly in the expansion joint near the bridge abutments,the pounding reduces the seismic response of piers but generates high magnitude and short duration acceleration pluses in the beams;（2） the pounding effect between adjacent beams will be enhanced when the longitudinal constraint effect of abutments is considered;（3） for the range of gap width usually adopted in design,the pounding phenomenon will inevitably occurs in strong earthquakes;（4） the sliding performance of bearings plays a role in isolation of the seismic response of piers,the times of impact between adjacent beams will be reduced when the sliding performance of bearings is considered;（5） the seismic responses of bridge will become very complicated because of the combined action of various nonlinear boundary conditions,these factors should be considered reasonably to get the real response of bridge.

关 键 词：桥梁工程 双柱式高墩 非线性时程分析 地震碰撞 接触单元 桥台刚度 支座滑动 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]