上跨运营铁路双层简支钢桁梁桥节点构造对比分析  

Comparative Analysis of Joint Structure of Double-Layer Simply Supported Steel Truss Bridge over Operating Railway

作　　者：唐志伟 Tang Zhiwei(China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600

出　　处：《黑龙江科学》2024年第4期77-79,83,共4页Heilongjiang Science

摘　　要：为研究钢桁梁桥节点处支管之间构造差异对结构静力性能的影响,以蒸汽管网双层简支钢桁梁跨越铁路工程为例,节点处支管构造原则存在一定的差异,通过建立Midas整体模型,对支管分离与支管搭接两种不同节点构造情况进行对比,分析杆件受力性能的差异。结果表明,支管分离与支管搭接对支点附近节点斜腹杆影响较大,支管分离时,下弦杆节点斜腹杆应力最大达262 MPa,比支管搭接时斜腹杆应力大85 MPa;上弦杆节点斜腹杆应力最大达279 MPa,比支管搭接时斜腹杆应力大66 MPa,不满足主+附荷载组合作用下拉杆容许应力260 MPa的要求,需进一步提高支点处斜腹杆的杆件尺寸,以满足规范要求。通过对比节点构造差异对结构静力性能的影响,有助于合理优化结构杆件设计,为类似工程提供参考。In order to study the influence of the structural difference between the branch pipes at the joints of the steel truss bridge on the static performance of the structure,the study takes the double-layer simply supported steel truss bridge crossing the railway project of the steam pipe network as the engineering practice.In the design of the double-layer simply supported steel truss bridge,there are some differences in the structural principles between the branch pipes at the joints due to different current specifications.By establishing the overall model of Midas,the differences in the mechanical properties of the members of the structure under the two different node structures of branch separation and branch overlap are compared and analyzed.The results show that the branch pipe separation and branch pipe overlap have great influence on the inclined web member near the fulcrum.When the branch pipe is separated,the maximum stress of the inclined web member at the lower chord node reaches 262 MPa,which is 85 MPa higher than that of the inclined web member when the branch pipe is overlapped.The maximum stress of the inclined web member of the upper chord node reaches 279 MPa,which is 66 MPa larger than that of the inclined web member when the branch pipe is lapped.It does not meet the requirements of the allowable stress of 260 MPa under the action of the main and attached load combination.It is necessary to further improve the bar size of the inclined web member at the fulcrum to meet the requirements of the specification.By comparing the influence of joint structure difference on the static performance of the structure,it is helpful to optimize the design of structural members and provide reference for similar projects in the future.

关 键 词：双层简支钢桁梁 节点构造 支管搭接 支管分离 静力分析 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]