独塔宽幅斜拉桥索塔锚固区传力性能分析

Mechanical behavior of cable-pylon anchorage of single pylon cable-stayed bridge with wide deck

为研究独塔宽幅斜拉桥索塔锚固区域钢锚箱与塔壁间的传力性能,以郑州农业路大桥受力最大的斜拉桥索塔钢锚箱MX16为研究对象,利用有限元软件MIDAS和ANSYS建立桥梁结构整体和局部钢锚箱模型,研究剪力钉间距、剪力钉刚度和钢锚箱腹板厚度对钢锚箱与混凝土塔壁传力机理的影响。研究结果表明:空间索力的竖向分力及横桥向水平分力靠剪力钉群传递到混凝土塔壁,顺桥向水平分力主要靠锚箱间的钢锚梁承担;增大钢锚梁腹板厚度可减小塔壁弯矩而减小剪力钉间距可减小应力集中均能改善塔壁受力,但增大剪力钉的刚度对混凝土塔壁受力影响并不显著。

In order to investigate the force transmission performance between the steel anchor box and the pylon wall in the anchoring zone of the single-pylon cable-stayed bridge with wide deck,the steel anchor box MX16 in the pylon of Zhengzhou Nongye Road Bridge,which is the most stressed,was used as the research object.The finite element software MIDAS and ANSYS were used to establish the globel model of the bridge structure and the local model of steel anchor box,respectively,to study the shear stud spacing,shear stud stiffness and steel anchor box web thickness on the transmission mechanism of the steel anchor box and the concrete pylon wall.The research results show that the vertical and horizontal components of the cable force are transmitted to the concrete pylon wall by the shear studs group,and the longitudinal components are mainly borne by the steel anchor beams between the anchor boxes.Increasing the thickness of the steel anchor beam web can reduce the bending moment of the pylon wall,while reducing the spacing of the shear studs can reduce the stress concentration,both of which can improve the force of the pylon wall.Increasing the stiffness of the shear studs has no significant effect on the force of the concrete pylon wall.