武汉市杨泗港快速通道跨线斜拉桥总体设计

Overall Design of the Overpass Cable-Stayed Bridge of Yangsigang Expressway in Wuhan

武汉市杨泗港快速通道跨线斜拉桥为(40+88+252+88+40)m半飘浮体系双独柱塔转体钢箱梁斜拉桥。该桥主梁采用流线型扁平整幅钢箱梁,梁长507m、高3.3m,桥面宽44m。桥塔为独柱型钢筋混凝土结构,塔高95.6m,塔柱采用矩形空心截面。下塔柱两侧设置牛腿式横梁,桥塔横梁高3～5.9m,为预应力钢筋混凝土结构。全桥共设72根(36对)斜拉索,斜拉索为中央双索面,采用标准强度1 670MPa的高强度平行钢丝拉索。索塔锚固采用齿块锚固方案,索梁锚固采用钢锚箱方案。桥塔下设双层矩形承台,承台下布置16根直径2.0m的嵌岩柱桩。该桥采用平转施工法跨越既有铁路,采用以球铰中心支撑为主、环道支撑为辅的转动体系,转体吨位达1.75万吨。桥面采用SS级和SX级双防撞墙防护体系。

The overpass cable-stayed bridge of Yangsigang expressway in Wuhan is a(40+88+252+88+40)m semi-floating cable-stayed bridge with double-single-column pylon and swivel steel box girder.The main girder of the bridge is composed of streamlined flat full-width steel box girders with a length of 507 m and a heigth of 3.3 m,and the width of bridge deck is 44 m.The pylon is made of single-column reinforced concrete which is 95.6 m high with a rectangular hollow section.An bracket beam is arranged on both sides of the lower pylon column,and the pylon beam is 3~5.9 m high,which is made of prestressed reinforced concrete.There are a total of 72(36 pairs)stay cables in the whole bridge.Central double cable planes and high-strength parallel steel cables with standard strength of 1 670 MPa are adopted as stay cables.The gear block anchoring is adopted in the anchorage zone of cable and pylon while the steel anchor box is adopted in the anchorage zone of cable and girder.There are double-layer rectangular caps under the bridge tower,and 16 rock-socketed columns with a diameter of 2.0 m are arranged under the caps.The flat-rotation construction method is adopted to span the existing railways.In the rotating system,the ball-centered central support is the main component and the auxiliary support of the ring road provides assistance.The tonnage of the rotating body reaches 17 500 tons.SS-level and SX-class double anti-collision wall protection system are used in the bridge deck.