鳊鱼洲长江大桥南汊航道桥主梁施工关键技术  

Key Construction Techniques for Main Girder of South Branch Navigation Channel Bridge of Bianyuzhou Changjiang River Bridge

作　　者：汪芳进[1] 张小川[1] WANG Fang-jin;ZHANG Xiao-chuan(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2022年第3期8-15,共8页Bridge Construction

基　　金：中国中铁股份有限公司科技研发计划项目(2018-重点-08)。

摘　　要：新建京港澳高铁安九段鳊鱼洲长江大桥南汊航道桥为主跨672 m双塔双索面钢-混混合梁交叉索斜拉桥,主跨及辅助跨主梁采用钢箱梁,标准节段长18 m,重约510 t,锚跨主梁采用预应力混凝土箱梁,重约200 t/m。根据该桥结构特点及水文地质条件,主梁采用现浇支架+多点顶推+单悬臂+双悬臂等混合方案施工。锚跨预应力混凝土箱梁采用“钻孔桩+钢管立柱+贝雷梁(大桥Ⅰ号桁梁)”支架现浇方案施工。九江侧钢梁采用单悬臂+多点顶推施工技术,边跨钢梁、合龙段与结合段同步顶推,省略了九江侧边跨合龙工序;在结合段钢梁与锚跨预应力混凝土梁之间设置锁定结构,保证了结合段施工质量。黄梅侧钢梁采用轻型墩旁托架+双悬臂+单悬臂施工技术,4号墩墩顶三节段采用轻型托架滑移施工,结合段采用浮吊整体吊装,定位后浇筑结合段混凝土,预应力张拉后进行边跨合龙;黄梅侧边跨和中跨合龙段均采用主动合龙,先边跨合龙后中跨合龙。The Bianyuzhou Changjiang River Bridge carries part of the Anqing-Jiujiang section of the Beijing-Hong Kong-Macao high-speed railway,the south branch navigation channel bridge of which is a two-pylon steel-concrete hybrid girder cable-stayed structure having a main span of 672 m and featuring the cross-over stay cables at midspan.The stay cables are fanned out in double cable planes.The superstructure of main and auxiliary spans consist of steel box girders,and a typical girder section measures 18 m long and weighs about 510 t.The superstructure of the anchor spans is composed of prestressed concrete box girders,weighing about 200 t/m.Given the structural characteristics and hydrogeological conditions,multiple construction techniques were selected to address specific requirements,including the scaffolding-supported casting,multi-point incremental launching,one-way cantilever assembly,and balanced cantilever assembly.The prestressed concrete box girders in the anchor spans were cast in-situ on the scaffolds formed of steel tubular posts and bailey trusses(TrussⅠdeveloped by China Railway Major Bridge Engineering Group Co.,Ltd.)and supported on bored pile foundation.The Jiujiang-bank steel girders were installed by the combined utilization of one-way cantilever assembly and multi-point incremental launching,while the steel girders in side spans,closure section and joint section were pushed out simultaneously,skipping the closure of Jiujiang-bank side spans.A locking device was set between the steel girder in the joint section and prestressed concrete girder in the anchor span to ensure the construction quality.The Huangmei-bank steel girders were installed via combined use of balanced cantilever assembly and one-way cantilever assembly,with the support of lightweight pier-side brackets.The three girder segments on the top of pier No.4 were slid into position by using lightweight brackets.For the joint section,the steel girders were hoisted and installed by the floating crane,once positioned,the concrete was cast,

关 键 词：斜拉桥 高速铁路桥 钢-混混合梁 钢箱梁 预应力混凝土梁 顶推施工 轻型墩旁托架 施工技术 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]