重庆油溪长江大桥760 m钢箱梁悬索桥设计

重庆油溪长江大桥建设条件极其复杂,跨江涉铁,且位于山区陡坡地段,综合考虑地形条件、行洪、通航及环保要求,该桥主桥采用760m钢箱梁悬索桥一跨跨越长江。加劲梁采用正交异性板流线型扁平钢箱梁,中心线处梁高3m(内高),梁宽30m(含风嘴),标准节段长15m。桥塔采用斜腿门式框架混凝土结构,设置上、下2道横梁,北岸桥塔采用不等高塔柱以适应地形,桥塔均采用灌注桩基础。北岸采用隧道式锚碇,位于深挖方路堑内;南岸采用重力式锚碇。主缆计算跨径为(210+760+240)m,每根主缆由112股91根直径5.0mm、强度1770MPa的预制镀锌平行钢丝组成,边跨不设吊索。对全桥进行整体计算,结果表明各项性能指标均满足规范要求。

Design of 760 m Steel Box Girder Suspension Bridge of Youxi Changjiang River Bridge in Chongqing

The construction conditions of the Youxi Changjiang River Bridge in Chongqing are extremely complex because the bridge crosses the Changjiang River is near railways, and is located on steep slopes in mountainous areas. In order to meet the comprehensive requirements of the topographic conditions, flood routing, navigation, and environmental protection, a 760 m steel box girder suspension bridge is adopted to construct the main bridge to span the Changjiang River. A streamlined flat steel box girder with orthotropic plates is adopted for the stiffening girder. The stiffening girder is 3 m high (inner height) at the center line, 30 m wide (including wind nozzles), and a standard segment is 15 m long. Inclined leg portal frame concrete structure is adopted in bridge tower, which contains two crossbeams (upper crossbeam and lower crossbeam). The north bank bridge tower consists of unequal tower columns to adapt to the topography. The cast-in-place pile foundation is constructed for the bridge tower. Tunnel-type anchorage is used in the north bank, which is located in a deeply excavated trench, and gravity-type anchorage is used in the south bank. The calculated span of the main cable is (210+760+240) m. Each main cable consists of 112 strands of 91 prefabricated galvanized parallel steel wires with a diameter of 5.0 mm and a strength of 1 770 MPa. No hanger is installed in the side span. The calculation results of whole bridge show that all performance indicators meet the requirements of specifications.