平潭海峡公铁两用大桥总体设计

Overall Design of Pingtan Strait Combined Bridges

平潭海峡公铁两用大桥是国内第一座公铁合建跨海大桥,兼顾高压电缆及自来水管搭载功能。大桥采用双线铁路+6车道高速公路标准建设,从长乐离岸下海至平潭上岛,依次跨越4条航道,全长约16.3 km,是目前世界上最长的公铁合建桥梁。3座主要航道桥均设计为钢桁混合梁斜拉桥,主跨依次为532,364,336 m,主墩基础采用?4.0 m和?4.5 m大直径嵌岩钻孔桩,钢桁梁首次采用两节间整段架设技术。深水高墩区桥梁设计为跨径80 m和88 m简支钢桁双层结合梁,采用整孔钢梁全焊、整孔浮运及吊装施工。浅水及陆地高墩区引桥采用跨径49.2 m混凝土箱梁,陆地低墩区引桥采用跨径40.7 m混凝土箱梁,全桥采用长栈桥加施工平台的施工方案,公路、铁路桥面均设置风屏障。

Pingtan Strait Combined Bridges is the first cross-sea bridge built both for highway and railway traffic in China,and it is designed for carrying high-voltage power line and water pipe.The bridge has 2 traffic decks.On the upper deck,there are 3+3 traffic lanes for highway traffic.On the lower deck,there are 2 railway tracks.It spans four navigation channels from offshore point Changle to landing point Pingtan Island with a total length of about 16.3 km.It is the longest road-rail bridge in the world.All the three main bridges are designed as steel truss hybrid girder cable-stayed bridges with main spans of 532 m,364 m and 336 m respectively.Large diameter rock socket bored piles with diameter of 4.0 m and 4.5 m are adopted for the pier foundations.Two steel truss girder segments are erected in one construction step for the first time.The bridge in deep water and high pier area is designed as a simple supported steel truss double deck composite girder with span of 80 m and 88 m.Whole welding technology,whole span floating and hoisting construction method are adopted.49.2 m concrete box girder is adopted for the approach bridge in shallow water and high pier area on land;correspondingly,40.7 m concrete box girder is adopted for the approach bridge in low pier area on land.Long trestle and steel platform are employed for the construction of the whole bridge.Wind barrier is set on both the bridge decks of highway and railway.