南京大胜关长江大桥主桥上部结构设计

Design of Superstructure of Main Bridge of Nanjing Dashengguan Changjiang River Bridge

京沪高速铁路南京大胜关长江大桥为主跨336 m的连续钢桁拱桥,设计速度目标值300 km/h,设计荷载为6线铁路荷载。主桁采用整体节点,弦杆采用箱形带肋杆件;桥面采用正交异性板整体钢桥面,分块制造、安装;为提高截面刚度、改善气动性能及增加阻尼,吊杆设计成八边形截面并预留阻尼器安装空间;平面及横向联结系采用刚度大、有利于3片主桁内力均匀分配的X形构造;使用墩旁托架及拉索辅助钢梁安装,利用拉索调整主跨合龙口位移。大桥施工进展顺利,2009年9月底主桥钢梁安装完成,预计2010年上半年达到铺轨条件。

Nanjing Dashengguan Changjiang River Bridge on Beijing-Shanghai High-Speed Railway is a continuous steel truss arch bridge with two main spans each 336 m. The designed target running speed for the Bridge is 300 km/h and the designed load is the six-track railway load. On the main trusses of the Bridge, the integral panel points are used, the chords of the trusses are of the box section members with ribs and the bridge deck is provided with the integral orthotropic steel deck which is manufactured and installed in segments. To increase the sectional rigidity and enhance the aerodynamic and damping performance of the Bridge, the hangers of the truss arches are designed into the octagon sections and the space for future installation of dampers is preserved. For the plane and lateral bracing systems, the X-shape connections that have great rigidity and that can facilitate the uniform distribution of the internal forces of the three main trusses are used. The truss girders of the Bridge are erected by the pier-side brackets in the aid of stay cables and are closed by adjusting the opening in between the girders at the main spans by the stay cables. The construction of this Bridge proceeded smoothly, the erection of the girders thereof were completed by the end of September, 2009 and it is anticipated that the rails can be laid in the first half of 2010.