Π形组合梁斜拉桥施工过程主梁应力分析方法  

Method for Stress Analysis of Main Girder During Construction of Π-Shaped Composite Girder Cable-Stayed Bridge

作　　者：刘洋[1,2] 周世军[1,3] LIU Yang;ZHOU Shi-jun(School of Civil Engineering,Chongqing University,Chongqing 400045,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [3]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《桥梁建设》2019年第3期63-68,共6页Bridge Construction

基　　金：国家自然科学基金项目(41702312)~~

摘　　要：为准确计算Π形组合梁斜拉桥施工过程中的主梁应力,基于能量变分原理建立了考虑轴力、弯矩、剪力滞相互耦合的有限梁段实用单元,提出了适用不同支承、不同边界条件下的有限梁段法主梁应力计算公式,对某主跨360m的Π形组合梁斜拉桥进行了实桥试验验证,并分析了该桥关键施工阶段的应力变化规律。结果表明:采用有限梁段法计算的主梁应力精度较高,钢主梁和混凝土桥面板的应力差异均在±3MPa内,与实桥试验的相对应力误差不超过5%;有限梁段法可以从整体上分析Π形组合梁斜拉桥施工全过程的主梁应力变化规律;关键施工阶段中钢主梁主要受拉,混凝土桥面板主要受压,且整个施工过程中混凝土板应力变化不大。In order to accurately calculate the stress of main girder during construction, we established a practical finite segmental girder element based on the energy variational principle after taking the mutual coupling of axial force, bending moment, and shear lag into account. Moreover, we put forward the stress calculation formulas of composite girder under the conditions of different boundary support and different load, verified the calculation formulas by real bridge tests on a 360 m Π-shaped composite girder cable-stayed bridge, and analyzed the stress variation law of the bridge during the key construction stage. The results show that the finite segmental girder method can be adopted to accurately calculate the stress of main girders, the difference in stress of the steel main girder and the concrete bridge deck is within ±3 MPa, and the relative difference between the calculation results and the actual bridge test does not exceed 5%. The finite segmental girder method can be adopted to analyze the stress variation law of the main girder during the whole construction process of Π-shaped composite girder cable-stayed bridge. In the key construction stage, the steel main girder is mainly in a tensile state, the concrete bridge deck is mainly in a compressive s tate, and the stress of the concrete deck negligibly changes during the whole construction process.

关 键 词：斜拉桥 Π形组合梁 有限梁段法 施工过程 应力 计算分析 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]