黄墩大桥索塔锚固区传力途径和受力分析

为验证索塔锚固区设计的合理性,了解索力在锚固区的传递途径以及主要板件的受力特点,通过全真的实体有限元模型对黄墩大桥索塔锚固区进行了计算分析。计算结果显示:锚固区的索力传递途径明确,能适应斜拉桥的受力特点;钢横梁两端受压,中间受拉,除锚固板与腹板的连接焊缝附近有应力集中现象外,其余板件的应力值均小于材料屈服强度;混凝土塔壁主拉应力较小,配置普通钢筋即可,不必设置环向预应力筋;位于牛腿焊缝附近的剪力钉受力较大,通过加密调整后满足受力要求。上述结果表明黄墩大桥索塔锚固区设计合理、实用,能满足结构受力需要。

Analyses on Force Transmission Route and Stresses in Cable-Pylon Anchorage Zone of Huangdun Bridge

The finite element model is used to calculate and analyze the cable-pylon anchorage zone of Huangdun Bridge in order to validate the design rationality of the cable-pylon anchorage zone and to understand the force transmission route and the stress characteristic of the main plate components in the cable-pylon anchorage zone.The calculation result shows that the force transmission route in the anchorage zone is clearly defined and can adapt the stress characteristic of the cable-stayed bridge.Two ends of steel cross beam are pressed and the middle is tensed.The stress values of the rest plate components are lower than the yield strength of material except the high stress zone near the welding line connecting the anchorage plate with the web.It is enough to install the plain steel bars because of smaller tensing stress in the concrete pylon wall,and it is not necessary to install the ring prestressed bars.The stress of shear studs is greater near the welding line of corbel,but can meet the requirement by adjusting the density.The above results make clear that the design of cable-pylon anchorage zone of Huangdun Bridge is reasonable and practical able to meet the stress demand of structure.