铁路下承式连续钢桁梁桥静动力性能评估  

Static and Dynamic Performance Evaluation of Railway Through Continuous Steel Truss Bridge

作　　者：杨仕力 王誉婷 吴科龙 洪彧[2] 李晓斌[2] 王强 YANG Shii;WANG Yuting;WU Keong;HONG Yu;LI Xiaobin;WANG Qiang(School of Architecture and Civil Engineering,Chengdu University,Chengdu 610106,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Chengdu Group Co.,Ltd.Chengdu 610081,China)

机构地区：[1]成都大学建筑与土木工程学院,成都610106 [2]西南交通大学土木工程学院,成都610031 [3]中国铁路成都局集团公司,成都610081

出　　处：《铁道勘察》2024年第2期1-7,共7页Railway Investigation and Surveying

基　　金：广西科技计划项目(AA21077011);四川省科技计划项目(2021YJ0054)。

摘　　要：成昆铁路复线完工后,部分老线区段将并入复线,并开行时速为160 km的动车组。为评估老线中典型桥梁在开行动车组后的服役性能,通过数值仿真及现场静动力荷载试验的方式,对某3×64 m连续钢桁梁桥的静力及动力性能进行检测与评估。研究表明,静力荷载作用下,主桁杆件最大轴向拉、压应力分别为143.1,175.4 MPa,均小于容许应力240 MPa,结构具有足够的强度安全储备。第34、35、36孔挠跨比分别为1/1 756、1/1 940、1/1 732,均小于规范规定的1/1 250,表明该桥具备通行动车组的刚度条件。各工况下活动支座纵向位移最大值为3.195 mm,小于支座纵向位移允许限值,表明各活动支座工作状态良好。动荷载作用下,主梁振型、自振频率与既有检定结果差异不大,且均小于理论计算值。主梁跨中竖向加速度、主梁跨中横向加速度、桥墩横向振幅及活动支座横向变形均满足规范要求,表明该钢桁梁桥主梁、桥墩及支座等主要组成部分的技术指标均满足行车要求。After the completion of the Chengdu-Kunming Double Track Railway,some sections in old line will be merged into the double track and multiple-unit trains with a design speed of 160 km/h will be put into operation.In order to evaluate the service performance of typical bridges in the old line after the operation of multiple-unit trains,the static and dynamic performance of a 3×64 m continuous steel truss bridge was tested and evaluated by numerical simulation,on-site static and dynamic load tests.The results show that under static load,the maximum axial tensile and compressive stresses of the main truss member are 143.1 MPa and 175.4 MPa,respectively,both are less than the allowable stress of 240 MPa.The structure has sufficient strength and safety reserves.The ratio of deflection to span of the 34th,35th,and 36th spans are 1/1756,1/1940,and 1/1732,respectively,which are less than the standard value of 1/1250,indicating this bridge has the stiffness conditions for passing motor train unit.The maximum longitudinal displacement of the movable support under each load case is 3.195 mm,which is less than the allowable longitudinal displacement limit,indicating the movable support is in good working condition.Under the action of dynamic loads,the vibration mode and natural vibration frequency of the main girder have little difference with the verified results,and are smaller than the theoretical calculated values.All the vertical acceleration of the main girder span,transverse acceleration of the main girder span,transverse amplitude of the pier and transverse deformation of the movable support meet the requirements of the specifications,indicating the technical indicators of the main girder,piers and supports of the steel truss bridge meet the requirements of train passaging.

关 键 词：成昆铁路 下承式连续钢桁梁桥 性能评估 静动力载试验 桥梁检测 

分 类 号：U239.9[交通运输工程—道路与铁道工程] U448[建筑科学—桥梁与隧道工程]