孔跨布置对大跨度铁路悬索桥刚度的影响研究  

Influence of Span Arrangement on Stiffness of Long-Span Railway Suspension Bridge

作　　者：苏朋飞 胡所亭 郭辉 孙大奇 SU Peng-fei;HU Suo-ting;GUO Hui;SUN Da-qi(National Sichuan-Tibet Railway Technology Innovation Center(Chengdu)Co.,Ltd.,Chengdu 612230,China;China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;Railway Engineering Research Institute,China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China)

机构地区：[1]国铁川藏科创中心(成都)有限公司,四川成都612230 [2]中国铁道科学研究院集团有限公司,北京100081 [3]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《桥梁建设》2023年第3期71-78,共8页Bridge Construction

基　　金：国家万人计划科研项目(2022WR001);中国铁道科学研究院集团有限公司基金项目(2021YJ084);中国国家铁路集团有限公司科技研究开发计划课题(K2021G020)。

摘　　要：为探究孔跨布置对大跨度铁路悬索桥刚度的影响规律,以某主跨1092 m的公铁两用悬索桥主桥为背景,采用MIDAS Civil软件建立不同数量边跨(0~4边跨)的悬索桥有限元模型,对5种模型的主跨竖向刚度、跨中横向位移及梁端变位等指标进行对比分析。结果表明:孔跨布置对大跨度铁路悬索桥的主跨竖向刚度、跨中横向位移、梁端竖向转角、梁端横向折角、梁端横向位移、梁端纵向位移和桥梁自振特性有较显著的影响,但随着边跨数量的增加,影响逐渐趋于收敛;孔跨布置对主缆重力刚度影响较小。大跨度铁路悬索桥无边跨时,桥梁的梁端竖向转角、横向折角和纵向位移均明显增大,设计时应慎重选用;单边跨时,桥梁的梁端横向位移较大(横向限位支座约束时,对应的横向反力较大),需采取相应措施;地形条件允许时,建议增加边跨数量,同时加强梁端位移荷载组合方法、长效控制措施和高性能梁端伸缩装置的研究。An existing rail-cum-road suspension bridge with a main span of 1092 m is applied as a case to study the influence of span arrangement on the stiffness of the long-span railway suspension bridge.Five finite element models of suspension bridges,one having no side span and the other four having one,two,three and four side spans,respectively,were built up in MIDAS Civil,to analyze their related main span vertical stiffness,midspan transverse displacement and girder-end deformation.It is shown that span arrangement is an essential factor in the long-span railway suspension bridge design,which significantly influences a series of indexes of the mechanical property of the bridge,including main span vertical stiffness,midspan transverse displacement,girder-end vertical rotation angle,girder-end transverse deflection angle and displacement,girder-end vertical displacement and natural vibration characteristics of bridge,however,the influential intensity gradually weakens as side spans are introduced,and usually the more side spans,the better.The gravity stiffness of main cables is not sensitive to the span arrangement.Equipped without a side span,the girder-end vertical rotation angle,transverse deflection angle and longitudinal displacement of the long-span railway suspension bridge are remarkably enlarged,which should be the least option.For a long-span railway suspension bridge with one side span,the girder-end transverse displacement is significant(restricted by the transverse limiters,the corresponding transverse reaction force is great),countermeasures are required.Terrain permitted,it is better to arrange side spans.Further research should focus on the method to alleviate the girder-end displacement by optimizing load combinations,long-term girder-end displacement control measures and developing high-performance girder-end expansion devices.

关 键 词：铁路桥 悬索桥 整体刚度 孔跨布置 梁端转角 梁端位移 自振特性 有限元法 

分 类 号：U448.25[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]