鳊鱼洲长江大桥南汊航道桥施工控制关键技术  

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

作　　者：李江刚[1] 石建华[1] 张巨生[1] LI Jiang-gang;SHI Jian-hua;ZHANG Ju-sheng(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056

出　　处：《桥梁建设》2022年第4期8-15,共8页Bridge Construction

基　　金：中国国家铁路集团有限公司科技研究开发计划项目(K2021G020)。

摘　　要：新建京港高铁安九段鳊鱼洲长江大桥南汊航道桥采用主跨672 m的双塔双索面钢箱混合梁交叉索斜拉桥,主跨及北辅助跨钢梁采用悬臂拼装架设,南辅助跨钢梁采用顶推施工,锚跨预应力混凝土梁采用支架现浇。该桥采用“多工序同步作业”,即双悬臂阶段塔柱与钢梁悬臂架设同步,单悬臂阶段桥面附属结构与钢梁架设同步,成桥后铺砟施工与调索同步。为了确保成桥内力及线形满足设计要求,采用3D Bridge有限元软件建立大桥计算模型,基于无应力状态法开展施工控制。针对钢梁自重在恒载中占比小、初期道砟容重低等特点,结合施工关键工序研究,采取钢梁无应力匹配制造、现场无应力安装、边跨与主跨主动合龙、斜拉索塔端锚杯加长设计、单节段内2对索异步张拉、交叉索分步安装、成桥后分2次调索等关键控制技术,实现了大桥精准、快速合龙,确保了“多工序同步作业”下的结构受力安全和线形控制。施工控制结果表明:考虑温度修正后实测线形与设计线形吻合,索力偏差小于10%,满足设计要求,成桥状态良好。The south branch navigation channel bridge of Bianyuzhou Changjiang River Bridge that carries part of the Anqing-Jiujiang Section of the newly-built Beijing-Hong Kong High-speed Railway is a two-pylon cable-stayed bridge with a main span of 672 m.The superstructure of the bridge is a hybrid of steel box girders and concrete box girders,and the stay cables are fanned out in double cable planes,with pairs of stay cables crossing over at midspan.The steel box girders in the main and north auxiliary spans were erected by the cantilever assembly method,while the steel box girders in the south auxiliary spans were incrementally launched,and the prestressed concrete box girders in the anchor spans were cast in situ on scaffoldings.The construction of the bridge was carried out in three phases:the balanced cantilever phase where the construction of pylon columns and cantilever assembly of steel girders were performed in parallel;the one-way cantilever phase where the installation of deck appurtenances and steel girders progressed synchronously;and the post-closure phase where the ballast placement and cable force tuning were conducted in a synchronized manner.To ensure that the internal forces and geometry of the completed bridge could meet the design requirements,the finite element software 3D-Bridge was used to establish the computing model,the bridge was brought under the construction control based on unstressed state method.Due to that the self-weight of steel girders accounts for a small portion of the total dead loads and the density of the ballast at the early age is low,the key construction procedure was studied,and multiple key control techniques were utilized to achieve the accurate and rapid closure of the bridge,including the unstressed matching fabrication and on-site unstressed installation of the steel girders,active side and main spans closure,using longer stay cable sockets in the pylons,unsynchronized tensioning of the two pairs of the cables force in a single segment,phased installation of crossover ca

关 键 词：铁路斜拉桥 混合梁 交叉索 同步作业 无应力状态法 线形 主动合龙 施工控制 

分 类 号：U448.13[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程] U445.4