平潭海峡公铁两用大桥栈桥设计  

Design of Trestle of Pingtan Straits Rail-cum-Road Bridge

作　　者：王东辉[1] 张立超[1] 

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430053

出　　处：《桥梁建设》2015年第4期1-6,共6页Bridge Construction

摘　　要：平潭海峡公铁两用大桥全长约16.34km,桥址处风大、海况条件恶劣、地质复杂。为提高海上作业工效,减少船机设备使用,大桥基础采用长栈桥辅助施工平台施工方案,将海上施工转化为栈桥及平台施工。针对栈桥设计难点,制定了栈桥荷载组合及设计原则,并根据水深及地质条件进行栈桥结构设计。栈桥全长7.49km,栈桥宽8.5m;水深≤35m,栈桥均采用钢管桩基础,35m<水深≤45m,栈桥基础采用"导管架+支承桩"结构。水深≤18m,栈桥跨径9m+15m,上部结构采用贝雷梁,钢管桩直径1.2m;水深>18m,栈桥跨径12m+32(28)m或12m+36m,上部结构采用大桥1号桁梁,钢管桩直径1.5,2,2.4m。为解决海洋环境下栈桥的耐久性问题,提出了预留钢管桩壁腐蚀裕量和管桩外表面涂装相结合的防腐设计。The Pingtan Straits Rail-cum-Road Bridge is totally about 16.34 km long. The wind at the bridge site is strong, the sea conditions are severe and the geology is complex. To improve the efficiency of the construction over the sea and to minimize the usage of the ships and relevant equipment, it was determined that the foundations of the bridge should be constructed by the scheme of the construction platforms aided by the long trestle so that the construction over the sea could be shifted to that on the trestle and platforms. In regard of the design difficulties of the trestle, the load combination and design principles for the trestle were formulated and the structure of the trestle was hence designed according to the different water depth and geological conditions. The trestle is totally 7.49 km long and 8.5 m wide. In the area of the water depth 435 m, the foundations of the trestle are the steel pipe piles while in the area of the 35 m%water depth445 m, the foundations are the structures of the ＂jackets＋support piles＂. For the trestle over the area of the water depth 418 m, the span arrangement of the trestle is 9 m＋15 m, the superstructure of the part of the trestle is the Bailey truss and the diameters of the steel pipe pipes are 1.2 m. For the trestle over the area of the water depth 〉18 m, the span arrangement of the trestle is 12 m＋ 32 （28） m or 12 m＋36 m. The superstructure of the part of the trestle is the Truss No. 1 used for the permanent bridge and the diameters of the steel pipe pipes are 1.5, 2 and 2.4 m. To provide solution to the durability of the trestle in the marine environment, the corrosion protection of the combined sacrificial protection layers of the steel pipe pile walls and the exterior coating of the piles was designed.

关 键 词：铁路公路两用桥 海上栈桥 荷载组合 结构设计 钢管桩 设计 桥梁施工 

分 类 号：U448.12[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程]