空间多点地震激励下简支梁桥碰撞响应数值模拟  

Numerical Simulation of Pounding Response of Simply-Supported Bridges Subjected to Spatially Varying Ground Motions

作　　者：何立翔 谢兴坤 任伟新 HE Lixiang;XIE Xingkun;REN Weixin(College of Field Engineering,Army Engineering University of PLA,Nanjing 210007,China;College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]陆军工程大学野战工程学院,江苏南京210007 [2]深圳大学土木与交通工程学院,广东深圳518060

出　　处：《陆军工程大学学报》2023年第5期68-75,共8页Journal of Army Engineering University of PLA

基　　金：国家自然科学基金(52208222,51278163);江苏省自然科学基金(BK20221529)。

摘　　要：为研究桥梁结构在空间多点地震激励下的碰撞响应,采用LS-DYNA建立了两跨简支梁桥三维精细化有限元模型,考虑了相邻桥跨之间面-面碰撞及偏心碰撞效应,计入了板式橡胶支座系统的非线性、钢筋混凝土在碰撞荷载作用下的材料非线性和应变率效应,详细分析了空间多点地震下桥梁上部结构的碰撞响应,研究了双向多点地震激励及局部场地效应对碰撞响应的影响。研究结果表明,碰撞会导致伸缩缝处桥梁上部结构的局部破坏;双向多点地震激励引起的桥梁偏心碰撞响应导致碰撞次数增加,但减小了碰撞力;局部场地效应对桥梁上部结构碰撞响应影响较大,基础场地条件越差,上部结构碰撞响应越大,碰撞引起的梁端局部破坏越严重。To investigate the pounding response of bridge structures subjected to spatially varying ground motions,the detailed 3D finite element model of a typical two-span simply-supported bridge was constructed using the finite element software LS-DYNA.The bridge model was constructed while taking into account the following factors,such as the surface-to-surface and eccentric pounding responses between adjacent bridge segments at the expansion joint,the non-linear behavior of the laminated rubber bearings and the non-linear material behavior including the strain rate effects of concrete and steel rebar.The pounding responses of the bridge superstructure under multi-component spatially varying earthquakes were investigated in detail.The effects of spatially varying bi-directional excitations and local site conditions on the pounding response were studied.The numerical results demonstrate that pounding may induce the serious local damages of the girders around the joints;the eccentric pounding response induced by the spatially varying bi-directional ground motions leads to the increasing of the pounding times whiel the decreasing of the pounding force;local site conditions have a significant influence on the pounding responses of the bridge superstructures;the worse site condition will lead to the larger pounding responses between bridge superstructures and the more serious local pounding damages to the end of the bridge girders.

关 键 词：碰撞响应 多点激励 面-面碰撞 局部场地效应 三维有限元分析 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]