跨断层简支梁桥地震响应分析及搭接长度研究  

Seismic response analysis and lap length study of simply supported beam bridge across faults

作　　者：岳伟勤 张来福 苏小波 王晨 王瑞涛 贾宏宇[3] YUE Weiqin;ZHANG Laifu;SU Xiaobo;WANG Chen;WANG Ruitao;JIA Hongyu(China Railway Changjiang Traffic Design Group Co.,Ltd.,Chongqing 401121,China;Chengdu Metro Operation Co.,Ltd.,Chengdu 610058,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中铁长江交通设计集团有限公司,重庆401121 [2]成都地铁运营有限公司,四川成都610058 [3]西南交通大学土木工程学院,四川成都610031

出　　处：《地震工程与工程振动》2024年第6期198-213,共16页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金面上项目(52178169);重庆市交通科技项目(CQDJT-CZKJ2023-02)。

摘　　要：为研究跨断层简支梁桥的地震响应和搭接长度需求,建立简支梁桥的弹塑性分析模型,通过动力响应分析、弹塑性分析和抗剪能力分析,研究了断层地震动的滑冲效应对简支梁桥搭接长度需求的影响,探讨了塑性铰破坏前墩梁相对位移与地面永久位移的关系。研究表明:断层位置会影响结构的地震响应,越靠近断层结构受到的地震影响越大;断层地震动的滑冲效应会增大结构的地震响应,断层地震作用下桥墩塑性铰区的最大剪力剪切强度比为0.47,桥墩的抗剪强度验算满足抗震设计规范要求;跨断层地震作用下结构的地震响应会出现漂移现象,导致塑性铰只往同一方向发展;多项式拟合的残差平方和与R^(2)值分别为539.910和0.984,地面永久位移为1.6 m时,塑性铰破坏前的墩梁相对位移为49.5 cm,约占规范计算搭接长度的56%,在峰值加速度较小的情况下,跨断层地震作用下简支梁桥的搭接长度需求满足规范要求。To study the seismic response and lap length requirements of the simply-supported bridge across faults,an elastic-plastic analysis model of the simply-supported bridge was established.Through dynamic response analysis,elastic-plastic analysis and shear resistance analysis,the influence of slip effect of fault ground motion on the lap length requirement of simple supported beam bridge is studied,and the relation between the relative displacement of pier beam and the permanent displacement of ground before plastic hinge failure is discussed.Research shows that the location of the fault affected the seismic response of the structure,and the closer the fault structure is,the greater the earthquake impact will be.The slip impact effect of fault ground motion increased the seismic response of the structure.The maximum shear strength ratio of the plastic joint area of the pier under fault earthquake action is 0.47.The checking calculation of the shear strength of the pier meets the requirements of the seismic design code.The seismic response of the structure under cross-fault seismic action drifted,resulting in the plastic hinge only developing in the same direction.The residual sum of squares and R^(2) of the polynomial fit are 539.910 and 0.984,respectively.When the permanent displacement of ground is 1.6 m,the relative displacement of pier and beam before plastic hinge failure is 49.5 cm,accounting for about 56%of the calculated supported length.When the peak acceleration is small,the supported length of the simply-supported beam bridge under the earthquake action across the fault meets the requirements of the code.

关 键 词：跨断层桥梁 塑性铰 搭接长度 滑冲效应 弹塑性分析 

分 类 号：TU433[建筑科学—岩土工程]