大跨钢⁃混凝土组合梁斜拉桥施工阶段受力性能分析  

Mechanical performance analysis of long⁃span steel⁃concrete composite beam cable⁃stayed bridge during construction

作　　者：田引安[1] TIAN Yin′an(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi′an 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《建筑结构》2022年第12期121-126,共6页Building Structure

基　　金：山区浅滩跨江大跨度悬索桥关键技术研究(TFSH⁃HJ.B⁃KY⁃1903⁃039)。

摘　　要：为了研究大跨钢⁃混凝土组合梁斜拉桥在施工过程中主梁与主塔的内力及位移变化规律,以江西药都大桥为例,采用ANSYS软件建立三维精细化有限元模型,对此钢⁃混凝土组合梁斜拉桥进行了施工过程数值分析。计算结果表明:在主桥最大单悬臂状态、合龙和桥面铺装后,主梁与主塔的应力、变形均满足相关规范要求。考虑斜拉索自重影响,通过Ernst公式对斜拉索的弹性模量进行修正,分析了几何非线性对结构内力和变形的影响。分析结果表明:随着斜拉索长度的不断变长,垂度效应越来越明显,尤其跨中斜拉索之间的主梁弯矩受到的影响较大,施工到桥合龙阶段,相对考虑垂度效应,不考虑垂度效应时,塔根部主梁弯矩减小1.6%;结构大位移及P⁃δ效应对主梁跨中挠度影响不超过4%。In order to study the internal force and displacement variation law of main girder and main tower of long⁃span steel⁃concrete composite beam cable⁃stayed bridge during construction,taking Jiangxi Yaodu Bridge as an example,the three⁃dimensional refined finite element model was established by ANSYS software,and the construction process of the steel⁃concrete composite beam cable⁃stayed bridge was numerically analyzed.The calculation results show that after the maximum single cantilever state,closure and deck pavement of the main bridge,the stress and deformation of the main beam and the main tower meet the requirements of the relevant specifications.Considering the influence of self⁃weight of stay cable,the elastic modulus of stay cable was corrected by Ernst formula,and the influence of geometric nonlinearity on internal force and deformation of structure was analyzed.The analysis results show that the sag effect becomes more and more obvious with the continuous increase of the length of the stay cable,especially the bending moment of the main beam between the mid⁃span stay cables is greatly affected.When the construction reaches the closure stage of the bridge,the bending moment of the main beam at the root of the tower decreases by 1.6%compared with that considering the sag effect and without considering the sag effect.The influence of structural large displacement and P⁃δeffect on the mid⁃span deflection of the main beam is not more than 4%.

关 键 词：大跨钢⁃混凝土组合梁斜拉桥 施工过程 悬臂拼装 垂度效应 大位移效应 荷载⁃位移效应 

分 类 号：TU398[建筑科学—结构工程] U443[建筑科学—桥梁与隧道工程]