行波效应对矮塔斜拉桥弹塑性地震响应的影响  

Effect of Traveling Wave on Elastic-plastic Seismic Response of Low-pylon Cable-stayed Bridge

作　　者：李小珍[1] 刘桢杰 雷虎军[2] 洪沁烨 

机构地区：[1]西南交通大学,成都610031 [2]福建工程学院,福州350118

出　　处：《铁道工程学报》2015年第11期49-54,共6页Journal of Railway Engineering Society

基　　金：国家自然科学基金(51378429);国家重点基础研究发展计划(973)(2013CB036301);国家高技术研究发展计划(863)(2011AA11A103)

摘　　要：研究目的：为探讨行波激励条件下铁路矮塔斜拉桥弹塑性地震响应的变化规律,基于弹塑性分析理论基础,本文以某主跨（144＋288＋144）m的铁路矮塔斜拉桥为工程背景,采用大刚度法实现多点激励以模拟行波效应,对比分析一致激励和行波激励（考虑不同剪切波速）条件下铁路矮塔斜拉桥弹塑性地震响应的差异。研究结论：（1）相比一致激励,行波效应会引起桥墩产生更大的弹塑性位移、弯矩响应及其非线性位移延性比（延性指标）,并使桥墩发生更大的塑性变形;（2）当剪切波速为200 m/s时,行波效应使9^#、10^#主墩福州与平潭侧薄壁墩身非线性位移延性比分别增大6.32%、17.90%、17.67%和33.92%,降低了其延性抗震能力;（3）进行类似结构延性抗震设计时,应考虑地震行波效应的影响;（4）该研究成果可用于指导桥梁延性抗震设计。Research purposes： In order to research the variation of elastic - plastic seismic response of railway low- pylon cable - stayed bridge under the excitation of traveling waves, based on the theoretical foundation of elastoplastic analysis and taking a railway low - pylon cable - stayed bridge with span arrangement 144 m ＋ 288 m ＋ 144 m as an engineering situation, the difference of elastic - plastic seismic response of bridge under uniform excitation and wave - passage excitation （ different shear velocity had been considered） simulated by large stiffness method was analyzed.Research conclusions： （ 1 ） The responses of elastic - plastic displacement, moment and nonlinear ductility ratio of displacement of piers are increased as well as its plastic deformation, compared with the situation of uniform excitation. （2） When shear velocity is 200m/s, the nonlinear ductility ratio of displacement of Fuzhou and Pingtan~ side of No. 9 pier and No. 10 pier have increased by 6.32% , 17.90% , 17.67% and 33.92% , which reduces the ductility seismic capacity of piers. （3） The effect of traveling wave should not be ignored when involving the ductility seismic design of similar structures. （4） The research results can be used in guiding for ductility seismic design of bridges.

关 键 词：矮塔斜拉桥 大刚度法 行波效应 弹塑性 

分 类 号：U24[交通运输工程—道路与铁道工程] TB123[理学—工程力学]