成昆铁路矮塔斜拉桥减隔震体系研究  

Research on Seismic Isolation System of Low Tower Cable-stayed Bridge in Chengdu-Kunming Railway

作　　者：马雅林[1] 任万敏[1] 朱敏[1] 孙帆[1] 李长年[1] MA Yalin;REN Wanmin;ZHU Min;SUN Fan;LI Changnian(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道标准设计》2023年第5期62-66,共5页Railway Standard Design

基　　金：中国中铁股份有限公司科技研究计划重大课题(2019-重大-02)。

摘　　要：成昆铁路金沙江大桥位于高烈度地震区,为跨度超过200 m的预应力混凝土矮塔斜拉桥,其减隔震体系关系到铁路运行的安全稳定性。为优化金沙江大桥的减隔震体系,利用MIDAS Civil软件对其支座结构进行有限元建模和计算,分析双曲面球形减隔震支座和三摩擦副双曲面球型减隔震支座及剪力榫结构的动力时程结果。研究结果表明:在罕遇地震下,双曲面球形减震支座结构能够有效减少主塔的墩底剪力和墩底弯矩,其位移大于400 mm,而桥梁纵向伸缩缝尺寸为300 mm,因此支座不满足桥梁纵向位移要求;三摩擦副双曲面球型减隔震支座墩底弯矩增大,墩顶位移和墩底剪力显著减小,墩顶位移为236 mm,小于纵向伸缩缝尺寸,桥墩间的内力相近,减小梁端伸缩量,有利于全桥的内力分布、梁端伸缩装置的设置及列车的平稳运行。In order to optimize the seismic reduction and isolation system of the low tower cable-stayed Jinsha River Bridge of Chengdu Kunming Railway in high intensity earthquake area,a finite element model is established with Midas civil software to analyze the dynamic time history of the bridge using hyperboloid spherical seismic reduction and isolation bearing and three friction pair hyperboloid spherical seismic reduction and isolation bearing.The results show that the shear force and bending moment under rare earthquake could be effectively reduced by means of the hyperboloid spherical seismic reduction and isolation bearing,resulting in displacement over 400 mm and 300 mm bridge longitudinal expansion joints,which fails to satisfy the limiting requirements of longitudinal displacement.While,the three friction pair hyperboloid spherical seismic reduction and isolation bearing can increase pier bottom bending moment,greatly reduce pier top displacement and pier bottom shear force with 236 mm pier top displacement less than longitudinal expansion joint,which contributes to the similar internal force between piers and the reduction of beam end expansion,and is conducive to the internal force distribution of the whole bridge and to the setting of beam end expansion device and smooth train operation.

关 键 词：铁路桥梁 斜拉桥 数值仿真 动力时程 减隔震体系 

分 类 号：U442.55[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]