淮河特大桥外倾式主塔施工临时支撑方案研究

Research on the Temporary Support Method for Construction of Extraverted Main Pylon of Huaihe River Bridge

摘要:

外倾式矮塔斜拉桥上塔柱施工时，在斜拉索未张拉前，上塔柱因自重在塔柱根部产生较大弯矩，临时支撑设置是改善塔底弯矩的有效方式。以淮河特大桥作为背景工程，对斜塔施工临时支撑方案进行了介绍，并建立了有限元分析模型，对比分析了不同支撑方案下塔柱受力性能。结果表明：无支撑状态下，塔柱根部拉应力较大，通过设置双肢斜塔间的临时支撑，根部拉应力显著减小；通过对钢管支撑和对拉索两种不同方案的对比，对拉索方案可以通过调整索力主动控制塔柱应力，同时与主塔连接更为简单。因此，采取了对拉索方案。

Abstract:

During the construction of the upper pylon of an extraverted short-pylon cable-stayed bridge, before the stayed cables are tensioned, the upper pylon generates a large bending moment at the root of the pylon due to its own weight. The setup of temporary support is an effective way to improve the bending moment at the root of the pylon. Taking the Huaihe River Bridge as the background project, the temporary support method for the construction of extraverted pylon is introduced, and a finite element analysis model is established. The stress performances of pylon under different support methods are compared and analyzed. The results show that in the unsupported state, the tensile stress at the root of the pylon is larger. By setting up the temporary support between double-limb extraverted pylons, the tensile stress at the root is significantly reduced. By comparing the two different methods of steel pipe support and opposite-pull cable, the opposite-pull cable method can actively control the stress of the pylon by adjusting the cable force, and the connection with the main pylon is simpler. Therefore, the opposite-pull cable method is adopted in this project.