渝黔铁路新白沙沱长江特大桥主桥施工技术  

Construction Technology for Main Bridge of New Baishatuo Changjiang River Bridge on Chongqing⁃Guiyang Railway

作　　者：幸思佳[1] 沈炫 XING Sijia;SHEN Xuan(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan,Hubei 430050,China;School of Civil Architecture and Environment,Hubei University of Technology,Wuhan,Hubei 430068,China)

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050 [2]湖北工业大学土木建筑与环境学院,湖北武汉430068

出　　处：《施工技术（中英文）》2023年第14期110-115,共6页Construction Technology

基　　金：中铁大桥局科研项目(桥经[2013]148号)。

摘　　要：渝黔铁路新白沙沱长江特大桥主桥为(81+162+432+162+81)m双层6线双塔双索面钢桁梁斜拉桥。针对该桥场地条件复杂、施工技术难度大的特点,主墩施工采用先平台后围堰施工方案,其中3号墩采用分段微差爆破清方的同时进行多功能水上钻孔平台拼装,并依托钻孔平台同步施工钻孔桩及围堰,有效缩短了关键线路工期;主塔下塔柱采用翻模法施工,中塔柱及上塔柱采用爬模法施工;主塔横梁利用钻孔平台桁架片作为现浇支架主梁进行现浇施工,实现了施工辅助结构重复利用;主桥上部结构施工中,重庆侧跨既有铁路边跨钢桁梁架设采用部分顶推施工方案,有效降低了钢桁梁架设对既有铁路运营的影响;贵阳侧主墩墩顶6节间钢桁梁采用单侧墩旁托架施工,剩余节间钢桁梁采用双悬臂对称施工,克服了施工现场无法使用大型浮式起重机的不足,并减少了墩旁托架工程量;斜拉索施工创新设计了张拉撑脚,取得了良好张拉效果;中跨合龙采用适配法施工,实现了钢桁梁高精度合龙。The New Baishatuo Changjiang River Bridge on Chongqing-Guiyang Railway is a cable-stayed bridge with a structure of steel truss girder which consists of double decks,six lines of railway and twin-tower double cable plan,the arrangement of main bridge spans is(81+162+432+162+81)m.In view of the complex site conditions and difficult construction technology of the bridge,the construction scheme of platform before cofferdam is adopted for the construction of the main pier.And the millisecond blasting is adopted for pier No.3,and the assembly of multi-functional drilling platform is carried out while removing reefs,and the drilling pile and cofferdam are constructed synchronously depends on the drilling platform,which effectively shortens the construction period of key lines.The lower tower column of the main tower is constructed by turnover formwork method,and the middle tower column and upper tower column are constructed by climbing formwork method.The cross girder of the main tower is cast-in-situ with the truss sheet of the drilling platform as the main girder of the support,which realizes the reuse of construction auxiliary equipment.For the superstructure construction of the main bridge,the side span steel girder crossing the existing railway in Chongqing adopts the partial incremental launching construction scheme,which effectively reduces the impact of the construction on the operation of the existing railway.The six joints steel girders at the top of the main pier at Guiyang side is constructed with single-sided pier side bracket,and the rest steel girders is constructed with double cantilever symmetrically,which overcomes the shortage that large floating crane cannot be used at the construction site and reduces the quantities of pier side bracket.In the construction of stay cable,the tensioning support is innovatively designed,and good tensioning effect is achieved.The middle span closure adopts the fitting method construction,which realizes the high-precision closure of steel girders.

关 键 词：桥梁工程 铁路桥 斜拉桥 钻孔平台 顶推 合龙 施工技术 

分 类 号：U445[建筑科学—桥梁与隧道工程]