大跨度三塔斜拉桥纵向约束体系设计研究  

Research on Longitudinal Restraint System of Long-Span Triple-Pylon Cable-Stayed Bridge

作　　者：王照伟 陈占力[3] 刘得运 李冲 WANG Zhao-wei;CHEN Zhan-li;LIU De-yun;LI Chong(Guangdong Provincial Highway Construction Corporation,Guangzhou 511447,China;Huangmaohai Link Administration Center,Guangzhou 511447,China;CCCC Highway Consultants Co.,Ltd.,Beijing 10088,China;CCCC Highway Bridges National Engineering Research Center Co.,Ltd.,Beijing 100088,China)

机构地区：[1]广东省公路建设有限公司,广东广州511447 [2]黄茅海跨海通道管理中心,广东广州511447 [3]中交公路规划设计院有限公司,北京100088 [4]中交公路长大桥建设国家工程研究中心有限公司,北京100088

出　　处：《世界桥梁》2021年第4期42-48,共7页World Bridges

基　　金：交通运输行业重点科技项目(2020-MS1-004);广东省交通集团科技项目。

摘　　要：针对三塔斜拉桥温度效应显著、整体刚度不足的特点,以黄茅海大桥[主桥为(100+280+720+720+280+100)m独柱塔双索面三塔斜拉桥,采用分体钢箱梁]为背景,采用非线性时程分析方法,对比分析不同纵向约束体系下斜拉桥的静、动力响应。结果表明:中塔通过设置弹性索实现弹性约束,单侧弹性约束刚度6.5×10^(5) kN/m,可起到塔梁固结的效果;在中塔采用弹性约束基础上,边塔采用纵向放松体系,每个边塔设置4个粘滞阻尼器[阻尼系数C为2500 kN/(m/s)α,速度指数α为0.3],明显改善了斜拉桥的静、动力响应;采用的中塔设置弹性约束-边塔设置阻尼器的组合结构体系,与全飘浮体系相比,梁端最大位移减小69%,边、中塔塔底弯矩分别减小40%、15%,与中塔固结体系相比,地震作用下组合结构体系梁端位移减小44%,中塔塔底弯矩减小51%,边塔塔底弯矩变化幅度较小,该组合结构体系合理。The application of the triple-pylon cable-stayed bridge is,to a certain extent,limited by the relatively strong temperature effect and weak overall stiffness of the structure.In this paper,the Huangmaohai Bridge is taken as a case to compare and analyze the static and dynamic responses of the triple-pylon cable-stayed bridge with different restraint systems,based on the non-linear time history analysis method.The bridge is a cable-stayed bridge with three mono-columned pylons that create span arrangement of 100,280,720,720,280 and 100 m,the stay cables are fanned out in double cable-planes,and the superstructure consists of two separated steel box girders.It is shown that when the single-side elastic restraint stiffness of the intermediate pylon reaches 6.5×10^(5) kN/m due to the addition of elastic stays,the bridge can be transformed to a pylon-girder fixation structure.Besides the elastic stays in the intermediate pylon,a longitudinal detensioning system is installed in each side pylon,namely to install four viscous dampers on each side pylon to significantly improve the condition of static and dynamic responses of the cable-stayed bridge,with damping coefficient C of 2500 kN/(m/s)αand velocity exponentαof 0.3.Compared with a full-floating system,the girder-end displacement is reduced by 69%,and the bending moments in the base of side and intermediate pylons are decreased by 40%and 50%,respectively.The proposed combined restraint system is also superior to the intermediate pylon fixation system,which can allow the girder-end displacement and bending moment in the intermediate pylon base to be reduced by 44%and 51%,respectively.The variation of bending moment in the base of the side spans is minor.The combined structural system is rational.

关 键 词：三塔斜拉桥 纵向约束体系 组合结构体系 弹性约束 阻尼器 设计参数 静动力性能 非线性时程法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程]