曲弦下承式钢管混凝土桁梁桥改造方案分析

Analysis of Transformation Plan of the Curved Chord Concrete Filled Steel Tubular Truss Bridge

针对某上跨铁路曲弦下承式钢管混凝土桁梁桥运营中出现桥面变形大的问题,利用桥梁专用软件建立数值分析模型,并结合桥梁静载试验数据,探讨桥面结构变形大的原因;本着少影响下方铁路运行、施工安全可行、节约投资,且能切实改善大桥运营状态的原则,提出简支变连续、加强横撑并增加吊索张拉横梁等措施,对桥面以上部位进行改造,同时对改造步骤给出建议;最后对改造效果进行理论分析.理论分析表明:改造后结构安全,且活载作用下横梁及桥面变形大幅度减小,改造效果显著.

In view of the problem of the bridge deck＇ s large deformation of a curved chord concrete filled steel tubular truss bridge, which is overpass over an electrified main line, bridge analytic software is firstly used to built finite model to analyze the old structure. In combination with static test results, the reason of the bridge deck＇ s large deformation is discussed. Then in line with some principles of little effect below the railway operation, construction safe and feasible, saving investment, and effectively improving the bridge operation state, the transformation plan is put forward. These plans are structure system transformation, strengthening transverse support and tension sling. The transformation steps are given too. Finally, the effect of transformation is analyzed and evaluated. Through analysis, it shows that structure after transformation is safety and the deformation of the bridge deck and the cross beam is greatly reduced. The effect of transformation is significant.