基于模型试验的曲线部分斜拉桥施工过程模拟分析

Simulation and analysis of the curved extra-dosed bridge construction based on model test

为研究曲线部分斜拉桥采用对称悬臂施工方法施工的结构受力特点,根据相似理论,对依托工程制作了1/40的全桥缩尺模型。通过模型试验模拟施工过程中主梁浇筑、斜拉索张拉、主梁合龙、桥面铺装等关键工序,并测试主梁截面应力及变形、斜拉索索力等关键断面随施工过程发展的变化规律。结果表明,有索区梁段在施工过程中顶、底板均呈拉压交替变化,实桥设计中应着重关注;模型桥的悬臂施工对称点的测试数据基本一致,表明该模型对称性较好;模型理论计算值与试验实测值规律吻合,验证了结构计算理论,且实测值均偏安全,表明模型结构刚度较大、安全性较高;理论模型与模型试验相结合对研究复杂结构的受力具有可行性。

In order to study the structure of the curved extra-dosed bridge with cantilever construction method, afull bridge model was made with the ratio 1/40 to the in-situ bridge based on the similarity theory. The variationsof the stress and deformation of girder and cable force under different construction loads such as main girder cast-ing, cable tension, closure, deck pavement in different construction process were measured. The results showthat the stress of top deck and bottom slab of girder in cable anchored area are in alternating tension-compressioncycles which should be laid emphasis on in practical designing. The calculated values of the model are in good a-greement with the experimental ones, which verifies the calculation theory. The cantilever construction of themodel bridge is symmetrical, with high rigidity and high safety. It is feasible to combine the theoretical model andthe model test for the research of the complex structure.