铁路混凝土槽形梁弯扭耦合效应分析与设计优化

摘要

Taking a single line 50 m concrete trough girder of Xining-Datong railway as an example,the structure characteristics of railway concrete trough girder were introduced,the bending and torsion coupling effect of straight-lined railway concrete trough girder under the action of curve load was analyzed.The accuracy of spatial plate and shell model for structural analysis and the current problems in the structure design of railway concrete trough girder were expounded.The results show that for the straight-lined railway concrete trough girder under curve loading,the plane frame model has defects.The analysis results of space plate and shell model are more comprehensive,which can accurately calculate the bending and torsion coupling amplif ication effect of trough girder.For the stress concentration problem of the joint position of girder and slab,the maximum stress in the whole bridge area can be obtained through the analysis of spatial solid model,then the relevant measures should be taken to optimize the structure or reinforcement ratio to reduce the local stress.%以西宁—大通铁路50 m单线混凝土槽形梁为实例,介绍铁路混凝土槽形梁的结构特点,分析直线混凝土槽形梁在曲线荷载作用下的弯扭耦合效应,阐述采用空间板壳模型进行结构分析的准确性和铁路混凝土槽形梁结构设计中普遍存在的问题.结果表明:对于铁路直线混凝土槽形梁曲线加载情况,平面杆系模型存在缺陷,空间板壳模型的分析结果较为全面,可以精确计算槽形梁弯扭耦合放大效应.对于梁板结合部位应力集中问题,可以通过分析空间实体模型得到全桥范围内该部位最大应力,从而采取相应措施优化构造或配筋率来降低局部应力.