外包钢壳混凝土异形索塔及其施工临时支撑研究

Research on External Steel Shell-Concrete Irregular Cable Tower and Its Temporary Construction Support

斜拉桥外包钢壳混凝土异形索塔结构受力复杂,在施工阶段存在变形和应力过大等问题。为保障该类索塔的施工安全和线形标准,设计了三种支撑方案以减小索塔的应力和变形,并利用有限元法对不同支撑方案的技术性能进行分析。分析结果表明,异形索塔的拱形轴线对塔柱应力和变形影响很大,不同建模方法计算的索塔应力和变形差异较大;三种方案的支撑均可显著减小索塔变形和腔内混凝土拉应力,而四道双管方案对降低施工难度和误差最有效;塔柱变形及混凝土拉应力对风压很敏感,施工时应加强塔柱抗风措施设计。

The external steel shell concrete special-shaped cable tower structure of cable-stayed bridges is subjected to complex forces,and there are problems such as deformation and excessive stress during the construction stage.To ensure the construction safety and linear standards of this type of cable tower,three support schemes were designed to reduce the stress and deformation of the cable tower,and the technical performance of different support schemes was analyzed using the finite element method.The analysis results show that the arch axis of the irregular cable tower has a significant impact on the stress and deformation of the tower column,and the stress and deformation of the cable tower calculated by different modeling methods vary greatly.The support of all three schemes can significantly reduce the deformation of the cable tower and the tensile stress of the concrete inside the cavity,while the four channel double pipe scheme is the most effective in reducing construction difficulty and errors.The deformation of tower columns and the tensile stress of concrete are sensitive to wind pressure,and the design of wind resistance measures for tower columns should be strengthened during construction.