组合索塔锚固区钢牛腿-塔壁作用机理分析

STRUCTURAL ANALYSIS OF STEEL BRACKET-CONCRETE WALLS IN CABLE-TOWER COMPOSITE ANCHORAGE

为揭示钢锚梁式组合索塔锚固区受力机理,基于连续弹性介质层法,推导了钢牛腿壁板-混凝土塔壁连接件作用剪力的理论计算式;通过三维弹簧元模拟焊钉连接件的作用,对实桥索塔锚固区进行混合元分析,验证了理论计算式的合理性。研究结果表明:由上节段钢锚梁累加竖向压力引起的钢壁板-塔壁连接件作用剪力在最底节段达到80kN;钢壁板上、下节段全连接时,与上、下节段全分离及三节段一联比较,底节段连接件作用较大集中剪力;各节段连接件作用剪力随钢壁板厚度、连接件抗剪刚度增加而增大。

To investigate the load transfer mechanism of cable-tower composite anchorage, a theoretical formula was established to calculate shear forces of connectors in the joint of steel bracket wallboard-concrete walls, based on the method of continuous elastic interlayer. The formula was verified by the hybrid finite element analysis of a cable-tower anchorage zone in a practical bridge, using a 3-dimensional spring element to simulate shear connectors. The results show that accumulated vertical compressive forces cause up to 80kN of a shear force for connectors in the lowest segment of steel wallboard-concrete walls. The maximum shear force of connectors is more concentrated in lower segments when steel wallboards are all connected from top to bottom, compared with those all separated or connected every 3 segments. In addition, the shear forces of connectors increase with the thickness of a steel wallboard and the shear stiffness of connectors.