混凝土收缩徐变对高、低塔混合梁斜拉桥成桥状态的影响分析  

Analysis of Influence of Concrete Shrinkage and Creep on Completed Bridge State of Hybrid Girder Cable-Stayed Bridge with High-Low Pylons

作　　者：杜文斌[1] 

机构地区：[1]中铁八局集团有限公司,四川成都610031

出　　处：《世界桥梁》2014年第1期27-30,共4页World Bridges

摘　　要：为了解混合梁斜拉桥混凝土收缩徐变对其成桥状态的影响,以某主跨520m,两桥塔塔顶高差86.5m,主跨为钢箱梁、边跨为混凝土箱梁的混合梁斜拉桥为背景,采用基于等效弹性模量及有效初应变的方法,分析混凝土收缩徐变对边跨混凝土梁段线形及主跨钢箱梁线形、应力及索力的影响。结果表明:混凝土收缩徐变对全桥线形及主梁应力影响较大,其中混凝土边跨挠度最大增幅达30%,主梁应力最大差值约5MPa;对全桥索力影响不大;顺桥向、竖向塔顶位移均约有2cm差别。To analyze the influence of concrete shrinkage and creep on the completed bridge state of the hybrid girder cable-stayed bridge, a hybrid girder cable-stayed bridge with a main span of 520 m was taken as the study background. The bridge has two pylons, and when measured from the tops of the two pylons, there is an 86.5 m height difference. The main span adopts steel box girder while the side spans are concrete box girder. The method based on equivalent elastic modu- lus and effective initial tensioning was employed to analyze the influence of concrete shrinkage and creep on the geometry of the concrete girder sections in the side spans and the deformation of the steel box girder in the main span, the cable forces and the stress in the box girder. The results of the analysis demonstrated that the concrete shrinkage and creep exerted great influence on the ge- ometry of the overall bridge and the main girder stress, specifically, the maximum increase rate of the deflection of the concrete side spans was up to 30% and the maximum difference value of the main girder stress was about 5 MPa, but the influence on the cable forces of the overall bridge was not great; there was a 2 cm difference between the pylon top displacement in the longitudinal bridge direction and that in the vertical direction.

关 键 词：斜拉桥 混合梁 桥塔 混凝土收缩徐变 成桥状态 应力 线形 

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]