钢管混凝土斜塔斜拉桥设计

金寨长征大桥主桥为(80+100)m斜塔斜拉桥。桥塔采用钢管混凝土组合结构,在钢管内部设置钢筋笼、钢管内壁焊接PBL纵向加劲肋及环向加劲肋,并灌注高性能混凝土,基础采用钻孔灌注桩;主梁采用钢箱结构;斜拉索呈扇形布置在中央分隔带内,单索面双排布置,斜拉索采用镀锌高强平行钢丝束,外层护套表面设置螺旋线以抑制风雨振;塔、墩、梁处钢-混结合段采用剪力钉、PBL连接键等,形成塔、墩、梁固结的约束体系。主桥采用临时墩辅助下的钢箱节段拼装方法施工。利用有限元软件对主桥进行整体结构计算,结果表明主桥的钢管混凝土桥塔、主梁、斜拉索应力均满足规范要求。

Design of Cable-Stayed Bridge with a Concrete-Filled Steel Tubular Inclined Pylon

The main bridge of Changzheng Bridge in Jinzhai County is a cable-stayed bridge with two spans of 80 and 100 m.The pylon is an inclined pylon,which is a concrete-filled steel tubular structure.Inside the steel tube,reinforcement cages are installed,PBL longitudinal stiffeners and circular stiffeners are welded to the inner walls of the steel tube,and high performance concrete is filled.The foundation of the pylon is formed of bored piles.The superstructure is comprised of steel box girders.The stay cables,located in the median zone,fanned out in pairs in a single cable plane.The stay cables are formed of galvanized high-strength parallel steel wires,each stay cable is encased with a protection sheath that has helixes to resistant rain-wind induced vibrations.Shear studs and PBL connectors were used in the pylon,piers,girders as well as the steel-concrete joint section to form a fixed restraint system of the pylon,pier and girder.The superstructure of the main bridge was constructed by the segmental assembly method with the assistance of temporary piers.The finite element software was used to do calculation for the overall structure of the main bridge.The results show that the stresses in the concrete-filled steel tubular pylon,main girder and stay cables all meet the code requirements.