三塔斜拉桥主梁节段施工非线性稳定性分析  

Nonlinearity Stability Analysis of Main Girder Segments of Three-Pylon Cable-Stayed Bridge at Construction Stage

作　　者：邓晓光[1] 卢志芳[1] 李倩[1] 

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,湖北武汉430070

出　　处：《桥梁建设》2015年第2期116-121,共6页Bridge Construction

基　　金：国家自然科学基金面上项目(51378405);高校博士点科研专项基金项目(博导类)(20110143110016);湖北省自然科学基金重点项目(2013CFA049)~~

摘　　要：针对传统的稳定性分析方法不能反映斜拉桥施工阶段各主梁节段的稳定性的问题,基于欧拉屈曲公式和斜拉桥几何非线性稳定分析理论,提出了一种考虑几何非线性的斜拉桥主梁节段稳定性分析方法,以武汉二七长江大桥为依托,对该三塔双索面半飘浮结合梁斜拉桥施工阶段各主梁节段的稳定性进行研究。采用MIDAS软件建立了该桥施工阶段全桥有限元模型,通过给单元施加轴力增量,反复迭代计算出主梁节段的有效长度和长细比,代入主梁节段的稳定性控制方程。结果表明：在最大双悬臂阶段时,中塔处主梁节段稳定性控制方程值为0.05-0.55,均满足规范要求,中塔支座处主梁节段是悬臂施工稳定性的关键控制部位。In view of the problem that the conventional stability analysis methods can not re‐flect the stability of the main girder segments of cable‐stayed bridge at construction stage and based on the Euler′s buckling formula and the geometric nonlinearity stability analysis theory of the bridge ,a kind of the stability analysis method considering the geometric nonlinearity for the main girder segments of the bridge was proposed .The Wuhan Erqi Changjiang River Bridge ,a semi‐floating system composite girder cable‐stayed bridge with three pylons and double cable planes , was cited as an example and the stability of the main girder segments of the bridge at the construc‐tion stage was studied .The software MIDAS Civil was used to create the finite element model for the w hole bridge of the bridge .By applying the axial force increment to the elements and iterative‐ly calculating ,the effective length and slender ratios of the main girder segments were obtained and were substituted in the stability control equation for the segments .The results of the study show that at the stage of the longest tw o‐side cantilever of the bridge ,the values of the stability control equation for the main girder segments nearby the intermediate pylon are 0 .05-0 .55 and can satisfy the relevant requirements in the codes .T he main girder segments nearby the bearing of the inter‐mediate pylon are the critical parts that should be controlled in the stability at the cantilever con‐struction stage .

关 键 词：斜拉桥 结合梁 几何非线性 有限元法 稳定性分析 

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