空间变化场地对超高墩铁路桥梁地震响应的影响  

Influence of Spatial Varying Site Conditions on Seismic Response of Ultra High-rise Pier Railway Bridge

作　　者：贾宏宇[1,2] 张克跃[1] 郑史雄[2] 李晰[1] 

机构地区：[1]西南交通大学土木工程系,四川峨眉山614202 [2]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》2014年第9期43-49,57,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金资助项目(51308465);中央高校基本科研业务费科技创新专项基金项目(2682014CX004EM)

摘　　要：为了研究空间变化场地对山区超高墩铁路桥梁抗震性能的影响,以贵州省境内一座超高墩铁路桥梁为工程背景,采用虚拟激励法对此超高墩铁路桥梁在空间变化场地条件下进行了抗震性能理论分析和数值模拟。考虑了多维地震动作用下,硬场地、中场地和软场地三种不同场地空间变化分布组合对此类桥梁随机地震响应的影响。研究结果表明:不同的场地分布组合对超高墩铁路桥梁地震响应影响不同,最高墩处的场地条件对结构响应的影响尤为明显;最高墩处为软场地,其他墩为硬场地时结构响应最大,为最不利工况,应予避免;对于超高墩铁路桥梁地震响应分析应充分考虑空间变化场地条件的影响因素,否则会低估地震作用下结构的响应。To study the effect of spatially varying site on seismic performance of mountainous ultra high-rise pier railway bridges,taking an ultra high-rise pier railway bridge located in Guizhou Province as an engineering example,the seismic performance analysis and the numerical simulation of this bridge subjected to spatial varying site conditions are conducted using pseudo excitation method. The influence of different spatial varying distribution combinations of firm,medium and soft site conditions on the stochastic seismic response of this kind of bridge under multi-directional earthquake excitations are considered for seismic analysis. The result shows that（ 1） different site condition distribution combinations have different influence on seismic response of ultra high-rise pier railway bridge,especially the influence of local site condition of the highest pier on structural response;（ 2） it is of great importance to avoid the most unfavorable condition that the soft soil condition beneath the highest pier,while hard soil beneath other piers;（ 3） the spatial varying site conditions should be considered in seismic analysis of ultra high-rise pier railway bridge structures subjected to earthquake action,otherwise structure responses could be underestimated.

关 键 词：桥梁工程 铁路桥梁 虚拟激励法 超高墩 空间变化场地 

分 类 号：U448.13[建筑科学—桥梁与隧道工程]