混凝土收缩徐变对简支变连续桥梁的影响

摘要

In order to explore the shrinkage and creep of concrete＇ influence on bridge transforming from simply supported into continuous girders, MIDAS/civil6.71 software was used to analyze its characteristics and estab- lish a model to calculate internal force and deformation pattern of arbitrary cross section at any time from the beginning of constructing bridge to the bridge in finished state within ten years through a specific project exam- ple. The shrinkage and creep of concrete＇ influence of stress and deformation on bridge transforming from sim- ply supported into continuous girders was studied according to the data changes of main beam＇ constant load bending moment. The results showed that the influence of creep on the cross deflection is biggest, two span deflection are bigger than that of the middle two span, the influence of creep on the intermediate fixed bearing negative bending is much bigger than that of the positive bending on the cross.%利用MIDAS／civil 6．71软件，针对先简支后连续桥的特性，运用具体工程实例，建立模型，计算出桥梁从开始施工到成桥以及成桥后十年的任意时刻任意截面的内力以及变形图形，通过整理主梁恒载弯矩数据的变化，分析了混凝土收缩徐变对简支变连续桥梁的受力和变形的影响，结果发现徐变对跨中的挠度影响最大，两边跨的挠度大于中间两跨的挠度，徐变对中间固定支座负弯矩的影响比跨中正弯矩的影响要大很多．