超宽幅主梁扭背索独塔斜拉桥总体设计  

Overall Design of Single Pylon Cable-Stayed Bridge with Very Wide Main Girder and Twisted Back Cable Planes

作　　者：张维[1] 付坤[1] 王维民[1] ZHANG Wei;FU Kun;WANG Wei-min(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《桥梁建设》2023年第S01期98-104,共7页Bridge Construction

基　　金：中交集团重大科技研发项目(2021-ZJKJ-08)。

摘　　要：厦漳同城大道沙洲岛特大桥西溪主桥采用(88+200)m扭背索独塔斜拉桥,塔墩梁固结体系。主梁采用钢-混混合梁,其中主跨为整幅钢箱梁,梁宽47 m;边跨为预应力混凝土箱梁,梁宽51 m;钢-混结合面位于主跨距桥塔理论跨径线15 m处。桥塔采用独柱式钢筋混凝土斜塔,总高134.6 m,桥塔向边跨倾斜8°,其下布置整体式承台,钻孔桩群桩基础。斜拉索采用标准抗拉强度1670 MPa平行钢丝拉索,边跨斜拉索为双索面空间扭背索,主跨斜拉索为准单索面。针对超宽桥面,采用空间梁格法分析剪力滞的影响,将混凝土梁纵腹板由6道增至8道。按3 m顺桥向标准间距设置钢箱梁实体式横隔板,可使该桥宽幅主梁偏载、扭转效应导致的应力增量控制在允许范围内。对塔墩梁结合部进行有限元精细化分析,针对应力集中情况,优化局部构造和配筋设计,经计算,优化后结构受力满足设计要求。The Xixi main bridge of Shazhou Island Bridge carrying a section of the Xiamen-Zhangzha Intracity Avenue is a single pylon cable-stayed bridge featuring its twisted back cable planes.The bridge has two spans of 88 m and 200 m,where the pylon fixed with the supporting pier and the superstructure.The superstructure consists of integral steel box girders in the main span that measure 47 m wide and prestressed concrete box girders in the side span with width reaching up to 51 m.The steel-concrete joint interface is arranged in the main span,15 m to the pylon.The pylon,rising 134.6 m in full height,is a mono-pole reinforced concrete pylon that inclines 8°towards the side span.The pylon is mounted on an integral pile cap that is in turn supported by bored piles.The stay cables are composed of parallel steel wires with nominal tensile strength of 1670 MPa.The stay cables in the main span are arranged in a typical single cable plane,while the stay cables in the side span are laid out in spatial twisted double cable planes.To address the very wide superstructure,a spatial grillage analogy method was employed to analyze the shear lag effect,consequently,the original 6 longitudinal webs of concrete box girders was modified to be 8.Inside the steel box girders,the solid diaphragms are spaced at 3 m along bridge length,to allow the stress increment caused by the eccentric and torsional effect of the very wide main girder to be in allowable range.The pylon-pier-girder joint section was analyzed by the refined finite element method.In accordance with the stress concentration conditions,the local structural configuration and reinforcement design was optimized.Calculations demonstrate that the mechanical property of the bridge structure after optimization meets the design requirements.

关 键 词：独塔斜拉桥 扭背索 超宽幅主梁 钢箱梁 斜塔 塔墩梁结合部 有限元法 桥梁设计 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程]