地震作用下简支梁桥纵向碰撞模拟  

Longitudinal Colliding Simulation of Simply Supported Beam Bridges under Ground Motions

作　　者：游四方 郑史雄[1] 贾宏宇[1] 赵灿晖[1] 杨光强 杨健[3] YOU Sifang;ZHENG Shixiong;JIA Hongyu;ZHAO Canhui;YANG Guangqiang;YANG Jian(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Guizhou Institute of Technology,Guiyang 550003,China;Guizhou Transportation Planning Survey and Design Academe Co.,Ltd.,Guiyang 550081,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]贵州理工学院,贵阳550003 [3]贵州省交通规划勘察设计研究院股份有限公司,贵阳550081

出　　处：《铁道标准设计》2020年第12期59-66,共8页Railway Standard Design

基　　金：四川省科技计划项目(2019YJ0243);国家自然科学基金项目(51308465,U1434205);中国博士后基金项目(2015M580031)。

摘　　要：为研究地震作用下简支梁桥纵向碰撞响应以及间隙宽度、碰撞刚度等因素对碰撞的影响,通过有限元软件SAP2000进行建模分析,首先通过接触单元法进行碰撞模拟,并对比各设计参数取值对碰撞的影响;其次基于大质量法,实现多点激励的输入模式,探究行波效应作用下桥梁响应的变化。研究表明:不同的结构设计参数对桥梁结构动力特性影响差异不尽相同,碰撞间隙对碰撞力的大小起控制作用;桥墩高度决定了桥墩是受弯矩还是剪力控制设计,墩高比为1.00和1.16时的墩底弯矩分别比墩高比为0.84时增加71.7%,73.5%,墩底剪力为墩高比取0.84时的53.9%,39.5%;刚度在不大于主梁刚度时对结构影响较小;行波效应中视波速越小,简支梁桥碰撞越严重。In order to study the longitudinal colliding response of simply supported beam bridge under ground motion,and the impact of factors such as gap width and collision stiffness on colliding,this paper uses the finite element software SAP2000 for modeling and analysis.Firstly,contact element method is employed for colliding simulation,and the influence of various design parameters value on colliding is compared.Secondly,based on the mass method,the input mode of multi-point excitation is realized to explore the changes of bridge response under traveling wave effect.The research results show that different structural design parameters have different effects on the dynamic characteristics of the bridge structure.The colliding gap plays a controlling role on the colliding force.The height of the pier determines whether the pier is subjected to the control of bending moment or shear force.When the pier height ratio is 1.00 and 1.16,the pier bending moment increases by 71.7%and 73.5%respectively compared with the pier height ratio of 0.84,and the pier bottom shear force becomes 53.9%and 39.5%when the pier height ratio is 0.84.The stiffness has little effect on structure when the stiffness is not greater than the stiffness of the main beam.The smaller the apparent wave velocity in the traveling wave effect,the more severe the simple beam bridge colliding.

关 键 词：地震作用 简支梁桥 纵向碰撞 Gap单元 接触单元法 行波效应 

分 类 号：TU311.3[建筑科学—结构工程] U441.3[建筑科学—桥梁与隧道工程]