千米级铁路悬索桥梁端支座位移长期变化规律分析  

Analysis of Long-Term Displacements of Girder-End Bearings of Rail-cum-Road Suspension Bridge with Main Span over 1000 m

作　　者：刘华[1] 刘兴旺 陈斌 LIU Hua;LIU Xing-wang;CHEN Bin(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China;China Railway Bridge&Tunnel Technologies Co.,Ltd.,Nanjing 210061,China;School of Civil Engineering,Southeast University,Nanjing 211102,China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056 [2]中铁桥隧技术有限公司,江苏南京210061 [3]东南大学土木工程学院,江苏南京211102

出　　处：《桥梁建设》2023年第3期48-55,共8页Bridge Construction

基　　金：国家重点研发计划项目(2016YFC0802202);江苏省科学技术厅项目(BE2018049)。

摘　　要：为掌握环境温度对大跨铁路悬索桥梁端支座位移及支座累计位移的影响,以某千米级公铁两用悬索桥为背景进行研究。基于该桥结构健康监测系统2021年的梁端支座位移长期监测数据,采用相关性基准值设定方法将梁端支座位移数据回归到合理区间,基于差分累加法获得支座累计位移,通过划分时段分析温度变化率对支座位移与环境温度间相关性的影响。结果表明:支座位移与环境温度间存在显著线性正相关关系;实测主梁伸缩系数和经验计算值基本吻合,全年南、北侧上游支座位移变化幅值和季度总累计位移基本一致,主梁两侧梁端变形具有高度的一致性;列车过桥时会导致主梁振动,支座大概率会发生小幅瞬间滑动现象,释放因主梁微小变形所产生的摩阻力;支座累计位移与桥梁结构体系有关,铁路悬索桥支座累计位移远小于公路缆索结构体系桥梁;温度变化率及其绝对值的大小对支座位移与环境温度间的相关关系存在一定的影响,温度变化率越稳定且绝对值越接近于0,两者相关关系越强。In this paper,the influence of ambient temperature on the displacements as well as accumulated displacements of girder-end bearings of the long-span railway suspension bridge is investigated,and an existing rail-cum-road suspension bridge with main span length surpassing 1000 m is used for a case study.The displacement data of girder-end bearings monitored in 2021 by the structural monitoring system of the bridge were selected and regressed to rational intervals with correlated base data,and then the accumulated displacements of bearings were obtained by using finite difference method,based on which the influence of temperature variation(in accordance with daily and annual time sections)on the correlation between displacements of bearings and ambient temperature was analyzed.It is shown that the displacements of bearings are in distinct positive linear correlation with ambient temperature,the measured main girder expansion and contraction coefficients basically agree with the theoretical values,the displacement variation range of bearings roughly comply with the accumulated displacements of bearings,and the deformations measured at the two ends of the main girder show consistency.The traveling train can cause the main girder to vibrate,which is more likely to induce instantaneous minor slide of bearings,thereby releasing the friction forces generated due to the minor deformation of main girder.The accumulated displacements of bearings are associated with the structural system of the bridge,as such,the accumulated displacements of bearings of a rail-cum-road suspension bridge is far less than that of a roadway cable-supported bridge.The temperature variation rates and their absolute values exert a degree of influence on the correlation between displacements of bearings and ambient temperature,thus a more stable temperature variation rate and/or the related closer-to-zero absolute value indicates stronger correlation between displacements of bearings and ambient temperature.

关 键 词：铁路桥 悬索桥 梁端支座位移 基准值 支座瞬时滑动 累计位移 温度变化率 相关性 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.36[交通运输工程—道路与铁道工程]