钢-混组合索塔锚固结构的力学行为及结构优化

为了解斜拉桥钢-混组合索塔锚固结构的力学行为并对结构设计进行优化，以重庆嘉悦大桥为依托，通过足尺模型试验及非线性有限元分析的对比分析，对钢-混凝土组合索塔锚固结构的力学性能、荷载传递机理进行了研究；采用正交试验方法对索塔锚固区混凝土主拉应力进行参数敏感性分析，进而提出了结构优化设计参数. 研究结果表明:钢锚箱与混凝土塔壁的应力水平较低，应力分布均匀流畅；钢锚箱与混凝土塔壁的相对滑移值均很小，最大值仅0.029 mm；剪力键的抗剪刚度对混凝土端塔壁的主拉应力水平有较为显著的影响，当刚度增加5倍，混凝土端塔壁主拉应力减少了17.3%；该桥所采用的组合索塔锚固区结构参数是安全、经济的. 

Mechanical Behavior and Structural Optimization of Steel-Concrete Composite Cable-Pylon Anchor

Full-size model test and nonlinear finite element analysis (FEA) are carried out to investigate the mechanical behavior and optimize the structure design of the steel-concrete composite cable-pylon anchor of Jiayue Bridge, Chongqing. The mechanical performance and load transfer mechanism of the steel-concrete composite cable-pylon anchor are studied first by the model test comparing with the nonlinear FEA. Then, the optimized structural parameters of the composite cable-pylon anchor are analyzed by FEA. Results show that the stresses of components of cable-pylon anchor are on a low level and distribute evenly. The relative slippage between anchor box and concrete pylon is small, and the maximum value is only 0.029 mm. The stiffness of shear connectors has a great impact on the principle stress of concrete pylon. When the stiffness is increased by 5 times, the principle stress of concrete pylon is reduced by 17.3%. The cable-pylon anchor’s structural design of Jiayue Bridge meet the requirement of safety and economics.