行波效应下多联长跨组合结构桥梁地震响应分析  

Seismic Responses of a Long Multi-Span Composite Bridge under Traveling Wave Excitation

作　　者：魏凯[1] 郭平[2] 韩萍[2] 袁万城[1] 曹新建[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]杭州市城市基础设施开发总公司,杭州310006

出　　处：《结构工程师》2010年第2期119-125,共7页Structural Engineers

基　　金：国家自然科学基金资助项目(50778131);国家自然科学基金资助项目(50978194)

摘　　要：以一座全长1855 m的多联长跨组合结构桥梁为背景,建立全桥空间杆系有限元模型,讨论了桩土相互作用简化模式对模型计算结果的影响,利用绝对位移法计算了该桥在多种行波激励工况下的地震响应,研究了激励输入模式、视波速、行波输入方向等因素对组合结构桥梁地震响应的影响规律,并通过计算,探讨了行波效应对多联长跨组合结构桥梁伸缩缝处联间相对位移的影响。研究表明,不同桩土相互作用简化模式对计算结果影响很大;行波效应会使组合结构桥梁结构位移尤其是支座变形及联间相对位移的地震响应增大,设计时应采取相应的改善措施。This paper presents the results of a study on the seismic response of a 1 855 m long multi-span composite bridge under traveling wave excitation.A nonlinear three-dimensional finite element spatial model of all the bridge was built.The effects of soil-pile interaction on the analysis result of the simplified model were discussed.The effects of the primary factors on the seismic responses of the bridge such as excitation pattern,wave velocity and spreading direction of the earthquake wave were investigated through a parametric study with absolute displacement method.The effects of seismic response at expansion joints under traveling wave excitation were also investigated.The major conclusions are that,the soil-pile interaction is so important that can not be neglected,the traveling-wave effect is generally found to be negative on the seismic responses of bearing deformation and relative displacement between girders,which become larger than that under uniform excitation,and some improvement measures should be taken into account in design.

关 键 词：组合结构桥梁 行波效应 地震响应 多联长跨 绝对位移法 桩土相互作用 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]