重庆南纪门长江大桥主桥总体设计

Overall Design of Main Bridge of Chongqing Nanjimen Changjiang River Bridge

重庆南纪门长江大桥为轨道专用桥,该桥主桥采用(34.5+180.5+480+215.5+94.5)m的高低塔双索面斜拉桥,半飘浮体系。主梁采用PK断面钢箱叠合梁,箱梁总宽23.6m,梁高3.3m。桥塔采用门形混凝土结构,北塔总高158m、南塔总高227m,基础为哑铃形承台接群桩基础。斜拉索采用1 860MPa高强平行钢丝,索塔锚固采用环向预应力,索梁锚固采用锚拉板。辅助墩及交接墩均采用板式桥墩。主梁采用悬拼施工,跨越南滨路及南滨国际段主梁化整为零分块拼装。为使桥位周边综合噪声满足环评标准,采取轨道设置钢弹簧浮置板减振道床+噪音敏感段设置全封闭声屏障+进出站车速控制在50km/h以内的减振降噪组合措施。

The main bridge of Chongqing Nanjimen Changjiang River Bridge,which is specially used for rail transit,is a cable-stayed bridge with two cable planes,it has one high pylon and one low pylon,and it is a semi-floating system with spans of(34.5+180.5+480+215.5+94.5)m.The main girder is a steel box composite girder with PK section,its total width is 23.6 m,and its total height is 3.3 m.A door-shape concrete structure is adopted in two bridge pylons,in which the north one is 158 m high and the south one is 227 m high,and the group pile foundation with dumbbell-shape cushion cap is adopted in foundation.The stayed cables,which are anchored to bridge pylons by circular prestressing tendons and anchored to girder by tensile anchored plates,are made of 1 860 MPa high-strength parallel steel wires.The auxiliary piers and junction piers are all plate pier type.The main girder is assembled by cantilever,and the section of the Nanbin road and Nanbin international is assembled by blocks.In order to ensure the noise around the bridge to meet the EIA standard,several measures,such as floating slab track bed with steel spring,fully enclosed sound barrier in noise sensitive areas,less than 50 km/h train speed around the station,are taken.