新洋港斜拉桥钢桁梁合龙精度敏感性分析

Closure Precision Sensitivity Analysis of Steel Truss Girder in Xinyanggang Cable-stayed Bridge

大跨度钢桁梁合龙过程中受到自重和其他荷载作用钢桁梁跨中变形较大,精准合龙较困难。本文以新洋港斜拉桥钢桁梁合龙施工为研究对象,通过理论计算和受力分析,探讨影响钢桁梁合龙精度的敏感性因素。为了防止钢桁梁合龙时内力及变形过大而影响工程结构的安全,应用MIDAS/Civil有限元软件对钢桁梁跨中纵向、横向、竖向受力和位移进行了模拟分析。结果表明:采用斜拉索索力调整、压重、导链对拉及顶拉等主要方法调整相应方向的位移,同时辅以使用长圆孔、合龙铰等措施,能够实现钢桁梁的精准合龙。

Due to the self-weight and other loads,the mid-span position of the steel truss girder was greatly deformed, resulting in difficulty of accurate closure of long-span steel truss girder. In this paper,the accurate closure at the middle point of the large-span steel truss girder of the Xinyanggang cable-stayed bridge was case-studied. Under the premise of ensuring the safety of the bridge structure,the closure precision sensitivity factors were discussed through theoretical calculation and mechanical analysis. To avoid threatening the structure safety due to significant inner force and deformation during closure of the steel truss,a finite element analysis was conducted using MIDAS/Civil. The steel truss girder was simulated in the longitudinal,transverse and vertical directions,and the force and deformation were calculated. The results show that the main adjustment measures such as adjusting cable force,counterweight,guide chain pulling in opposite direction and pushing and pulling,and auxiliary measures using long round holes and closure hinges,can achieve accurate closure of steel truss girder.