铁路斜拉桥减隔震方案参数优化研究  

Study of Parametric Optimization of Vibration Mitigation and Isolation Scheme for Railway Cable-Stayed Bridge

作　　者：黎璟 钱永久[1] 杨华平 金聪鹤 LI Jing;QIAN Yong-jiu;YANG Hua-ping;JIN Cong-he(School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China;School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]成都大学建筑与土木工程学院,四川成都610106

出　　处：《桥梁建设》2019年第5期45-50,共6页Bridge Construction

基　　金：中国工程院咨询研究项目（2015-05-ZD-002）;四川省应用基础研究重点项目（2017JY0059）~~

摘　　要：为研究不同设防烈度下铁路斜拉桥合理的减隔震方案及参数优化方法,以某主跨432 m斜拉桥为背景,采用SAP 2000软件建立该桥有限元模型进行非线性动力时程分析,对比多级设防烈度下摩擦摆支座、粘滞阻尼器、弹性索3种减隔震装置在不同参数组合下的减隔震效率。结果表明:摩擦摆支座在设防烈度高时不适用于半飘浮体系斜拉桥,在设防烈度较低时能一定程度控制地震响应,此时摩擦摆半径应考虑对行车平顺性的影响选取较大值;合理的粘滞阻尼器方案能有效降低铁路斜拉桥的内力与位移响应,阻尼器设计参数与目标设防烈度相关,可首先选定阻尼常数 C 的初值,再依据内力响应随速度指数α的变化趋势进行优化;弹性索能显著抑制梁端位移响应但会增加塔底弯矩响应,其刚度选取时宜将初始进入强相关区间或稍大的弹性刚度值作为最优刚度。To study reasonable vibration isolation and mitigation schemes and parameter optimization methods for railway cable-stayed bridge under different fortification intensities, a cable-stayed bridge with a main span of 432 m was taken as the study background. The software SAP 2000 was used to establish the finite element model of the bridge to analyze the non-linear dynamic time history of the structure. The vibration mitigation and isolation efficiencies of three types of devices, including the friction pendulum bearings, viscous dampers and elastic cables, were analyzed and compared, under multiple degrees of fortification intensity and different parameter combinations. The results show that friction pendulum bearings are not suitable to the cable-stayed bridge of half-floating system when the fortification intensity is high. But when the fortification intensity is low, the friction pendulum bearings can control the seismic response of the structure to a certain extent, under such circumstance, the radius of the pendulum should be set at a relatively large value, given its influence on the riding comfort. A rational viscous damper scheme can effectively reduce the internal forces and displacement responses of the railway cable-stayed bridge, the design parameters of the dampers are related to the target fortification intensity. The value of damping constant C can be optimized from the given initial value in accordance with the variation tendency of the internal force responses against the speed index α. The elastic cables can significantly suppress the girder-end displacement response, but will intensify the bending moment in the pylon base. The value of rigidity of cables can be determined by setting the initial value in the strong related range, or drawing the bigger elastic rigidity value as the optimum rigidity.

关 键 词：铁路桥 斜拉桥 减隔震设计 参数优化 摩擦摆支座 粘滞阻尼器 弹性索 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U441.3[交通运输工程—道路与铁道工程]