铁路斜拉桥锚拉板力学性能研究及创新

潜江铁路支线岳口汉江特大桥主桥为(32.7+50+93.7+260+38.2) m独塔双索面混合梁斜拉桥,斜拉索在钢箱梁上的锚固形式采用锚拉板式,考虑到铁路桥疲劳荷载较大,本桥采用与拉板连接的承压板构造形式,套筒上设置加劲肋。为保证锚拉板构造连接可靠,力线传递流畅,对比分析锚拉板组成构件不同关键参数的有限元计算结果,确定锚拉板结构关键参数取值。结果表明:拉板与拉筒连接焊缝圆弧过渡区应力集中较为明显,锚拉板受力不均匀性较大,其锚下应力向套筒及拉板传递存在一定的扩散范围,锚拉板其他部分应力及疲劳应力水平较低,满足规范要求;加大锚拉板与套筒连接焊缝根部的圆弧半径,可以有效改善锚拉板的应力集中现象,锚拉板过渡区采用150mm的1/4圆弧形式,并在圆弧与拉索套筒之间设置50 mm直线段。

Research and Innovation on Mechanical Properties of Anchor Plate of Railway Cable-stayed Bridge

The main bridge of Yuekou Hanjiang Bridge on Qianjiang Railway Branch Line is a cable-stayed bridge with single tower, double cable planes and with span arrangement of(32.7+50+93.7+260+38.2) m. The anchoring form of the stay cable on the steel box girder adopts the anchor pull plate. Considering the large fatigue load of the railway bridge, the bridge adopts the structure of bearing plate connected with tension plate, and stiffening ribs are installed on the sleeve. In order to ensure reliable connection and smooth transmission of force lines, the finite element calculation results of different key parameters of anchor plate components are compared and analyzed, and key parameters of the anchor plate structure are determined. The results show that the stress concentration in the arc transition zone of the weld joint between the pull plate and the pull barrel is obvious, and the stress distribution of the anchor plate is not uniform. There is a certain diffusion range of the stress under the anchor to the sleeve and the pull plate. The stress and fatigue stress of other parts of the anchor plate are low, which meets the requirements of the code. Increasing the arc radius at the root of the weld between the anchor plate and the sleeve can effectively improve the stress concentration of the anchor plate. The transition zone of the anchor plate adopts a 150 mm 1/4 arc form, and a 50 mm straight line segment is arranged between the arc and the cable sleeve.