铁路自复位高墩的高阶模态贡献研究  

High modal contribution of self-centering railway tall pier

作　　者：杜骞[1] 夏修身[1] 陈兴冲[1] 孙学先[1] DU Qian;XIA Xiu-shen;CHEN Xing-chong;SUN Xue-xian(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院

出　　处：《振动工程学报》2019年第6期1003-1010,共8页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51368033,51668035);兰州交通大学优秀平台支持(201801)(lzjtu(201801)EP support)

摘　　要：针对高阶模态对自复位桥墩的影响,以某铁路58 m高墩为例,基于OpenSEES建立自复位高墩地震反应模型。输入近场地震动强震记录,通过增量动力分析得出了墩身塑性铰的形成及发展规律。基于模态分解法讨论了前3阶模态对墩身弯矩和墩顶位移的影响,引入一种定量指标评价了各阶模态反应的贡献。结果表明:在近场地震作用下,自复位高墩墩底提离后只会减小第1阶模态响应对墩身的作用,使墩底不出现塑性铰;受高阶模态地震响应的影响,墩身中部仍会出现塑性铰区,墩底提离不能消除高阶模态的作用。To study influence of high order modal on self-centering bridge pier,this paper takes a 58-m railway tall pier as an example,and establishes a seismic response model of self-centering tall pier based on OpenSees.Inputting near-field ground motion records,the formation and development rule of plastic hinge in the pier are given through IDA analysis.Impact of the first 3 order modals on bending moment of pier body and pier top displacement is analyzed based on modal decomposition method,and a quantitative index is introduced to evaluate contribution of each order modal reaction.The results show that under the action of near-field earthquake,after lift-off of self-centering tall pier,only effect of the first mode response on pier body is reduced and no plastic hinge will appear at pier bottom.Influenced by high order modal seismic response,plastic hinge region still occurs at the middle of pier.Lift-off of pier bottom can′t eliminate effect of high order modal well.

关 键 词：自复位高墩 高阶模态 振型贡献率 地震反应 

分 类 号：U24[交通运输工程—道路与铁道工程]