小半径曲线桥T梁施工阶段异常横向位移分析及处理  

Analysis and Treatment of Abnormal Lateral Displacement of Sharp-Radius Curved Bridge During T Beam Construction

作　　者：王一光 郑元勋[2] WANG Yiguang;ZHENG Yuanxun(Henan Provincial Communications Planning&Design Institute Co.,Ltd.,Zhengzhou 451460,China;School of Water Conservancy and Transportation,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]河南省交通规划设计研究院股份有限公司,河南郑州451460 [2]郑州大学水利与交通学院,河南郑州450001

出　　处：《桥梁建设》2023年第5期145-150,共6页Bridge Construction

基　　金：国家自然科学基金项目(51878623)。

摘　　要：为解决小半径曲线桥T梁施工阶段梁体异常横向位移的问题,以某高速公路匝道小半径装配式T梁桥为背景进行研究。利用MIDAS Civil软件建立该桥第2联及第3联的有限元模型,分析3种工况(原设计成桥状态、梁端间隙处刚性填充并保持支座约束、梁端间隙处刚性填充并释放支座约束)下,不同温度作用(整体升、降温10、20、30℃)、横向温度梯度和汽车离心力对桥梁结构主梁支承点横向位移和支座横向剪力的影响。结果表明:原设计成桥状态工况下桥梁位移及内力均正常,但对梁端间隙进行刚性填充后,各墩支座在横向温度梯度及整体升温作用下的横向剪力远大于支座横向水平承载力,导致支座发生剪切破坏无法提供有效约束。根据分析结果,解除了梁端处刚性填充,保持梁端设计间隙,并按主梁原设计位置横向纠偏复位,同时对发生剪切破坏的支座进行了更换。采取以上处理措施后,该桥异常横向位移问题已得到解决,桥梁正常运营并且状态良好。The study focuses on the abnormal displacement of the sharp-radius curved bridge during the construction of T beams.The case bridge is an existing sharp-radius highway ramp bridge.Finite element models of the second and third continuous units of the bridge were built up in MIDAS Civil,to analyze the the superstructure lateral displacement at supports and the lateral shear forces of bearings under three loading conditions,specifically in the original design completed bridge state,when the girder-end fissures are rigidly filled and the bearings work efficiently,and when the girder-end fissures are rigidly filled and the bearings are released.And the influences of multiple factors were also investigated,including thermal effect(when temperatures of the structure are increased and decreased by 10,20,and 30℃,respectively),lateral temperature gradient and vehicle eccentricity.It is shown that in the original design state,the displacement and internal forces of the bridge all keep in normal conditions,but when the beam-end fissures are rigidly filled,the lateral shear forces of bearings at each support are far greater than the lateral load bearing capacity of bearings under the effects of temperature gradient and overall temperature rise,consequently the bearings were sheared to fail and lost efficient restriction to the structure.As per the analysis,the beam-end rigid fill was removed to leave the original design fissure at girder ends and to restore the structure to the design position.The failed bearing were replaced.By implementing the proposed treatments,the abnormal lateral displacement of the ramp bridge was rectified,and the bridge had been in good serving condition after the rehabilitation.

关 键 词：小半径曲线桥 装配式桥 T梁 横向位移 支座横向剪力 有限元法 处理措施 

分 类 号：U448.212[建筑科学—桥梁与隧道工程] U445.71[交通运输工程—道路与铁道工程]