单索面斜拉桥内力分布特征及荷载传递机理研究

Study of Internal Force Distribution Property and Load Transfer Mechanism of Cable-Stayed Bridge with Single Cable Plane

为研究单索面斜拉桥的受力特性,以东水门长江大桥(采用正交异性钢桥面板的单索面斜拉桥)为背景,采用ANSYS软件建立全桥三维有限元模型,计算上、下层桥面沿纵向和横向的轴力、剪力及弯矩分布规律,分析上、下层桥面及腹杆的最大、最小主应力。结果表明:上层桥面沿纵向轴力和剪力在斜拉索及桥塔处取得极值,沿横向轴力变化不大,剪力和弯矩在中纵梁处取得最大值;下层桥面沿纵向轴力在跨中及桥塔处取得极值,沿横向轴力变化不大,剪力和弯矩分别在桥面中部和侧边取得最大值;受斜拉索索力影响,上层桥面锚箱附近易发生应力集中,应力向两侧均匀传递,下层桥面荷载主要通过腹杆内、外侧进行传递,腹杆应力峰值在其两端与节点板连接处。

Abstract： To study the load bearing behavior of the cable stayed bridge with single cable plane, the Dongshuimen Changjiang River Bridge, a cable stayed bridge with single cable plane and with orthotropic steel deck, was taken as the study background. The ANSYS software was used to establish the finite element model of overall bridge, to calculate the distribution law of the axle load, shear force and bending moment in the upper and lower decks along transverse and longitudinal direction respectively, and analyze the maximum and minimum main stresses in the upper and lower decks as well as the web members. The results demonstrate that the axle load and shear force in the upper deck along longitudinal direction reach the limit values at the locations of stay cables and the pylons, the axle loads do not show significant change in the transverse direction, and the shear force and bending moment reach the maximum values at the locations of central stringers. In the lower deck, axle loads along the longitudinal direction reach the limit values in the midspan and at the pylons, but show no sign of distinct change along transverse direction, and the shear force and bending moment reach the maximum values in the central part and the edges of the deck. Due to the influence of stay cable forces, stress concentration is easy to occur near the anchor boxes in the upper deck, and the stresses are uniformly transferred to the two sides. Whereas, the loads in the lower deck are mainly transferred through the inner and outer sides of web members, the peak stress values in the web members occur in the connecting parts of the two sides of the web member and the gusset plates.