鳊鱼洲长江大桥北汊航道桥施工关键技术  

Key Construction Techniques for North Navigation Channel Bridge of Bianyuzhou Changjiang River Bridge

作　　者：郭航 陈开桥 王同民 马学平 GUO Hang;CHEN Kai-qiao;WANG Tong-min;MA Xue-ping(The Seventh Engineering Co. ,Ltd. ,China Railway Major Bridge Engineering Group,Wuhan 430056,China)

机构地区：[1]中铁大桥局第七工程有限公司,湖北武汉430056

出　　处：《世界桥梁》2021年第6期14-20,共7页World Bridges

基　　金：中铁大桥局集团有限公司科学技术研究与开发项目(2018-01-重大)。

摘　　要：鳊鱼洲长江大桥北汊航道桥为(49+140+140+49)m独塔平行索双索面预应力混凝土斜拉桥,主梁为单箱六室预应力混凝土箱梁,桥塔采用高129.647 m的H形钢筋混凝土结构,采用Φ2.5 m钻孔灌注桩基础。施工栈桥为“钢管桩+分配梁+贝雷梁+钢桥面板”结构形式,针对较厚覆盖层、深冲刷环境,通过设置斜桩和钻孔平台以及局部片石抛填增强其稳定性、安全性。针对溶洞极其发育区域的超深孔钻孔灌注桩(部分钻孔孔深超过150 m),采用“旋挖钻+旋转钻”接力复合成孔工艺成功克服钻孔桩施工难题。桥塔斜拉索锚固区设计为环向预应力体系,采用桥塔劲性骨架与环向预应力整体预制吊装工艺提高施工质量及工效。主跨梁采用大吨位宽幅牵索挂篮施工,挂篮在塔下异位拼装、横移、提升。为满足主梁快速施工要求,采用部分钢筋、内箱模板支架预制并整体吊装的施工工艺,大幅缩短了施工时间。The north navigation channel bridge of Bianyuzhou Changjiang River Bridge is a mono-pylon prestressed concrete cable-stayed bridge with two spans of 49 m and two spans of 140 m.The stay cables are arranged in parallel double cable planes.The superstructure consists of six-cell prestressed concrete box girders.The pylon is a H-shaped reinforced concrete structure rising 129.647 m,supported on foundation of 2.5 m-diameter bored piles.Trestles were built to facilitate the construction access,which were formed of steel pipe piles,spread beams,bailey trusses and steel deck plates.To suit the deep overburden and scouring environment,batter piles,borehole drilling platform were employed and local reclamation was performed by riprapping to improve the stability and safety of the trestles.Due to that the bored piles are long(some exceed 150 m in length)and located in the well-developed karst region,a borehole formation technique of combined use of rotary excavation and rotary drilling was selected.The stay cables are anchored to the pylon with a loop prestressing system.The stiffening skeleton in the pylon and the loop prestressing tendons were integrally prefabricated and hoisted to improve the construction efficiency.The concrete box girders in the main span were constructed using large-tonnage and wide cable-supported form travelers.The form travelers were assembled under the pylon,then transversely moved and lifted.To meet the requirements of rapid superstructure construction,a portion of reinforcement,supports of inner box formwork were prefabricated and integrally hoisted,which greatly shortened the construction time.

关 键 词：斜拉桥 栈桥 超深孔钻孔灌注桩 环向预应力锚固体系 大吨位宽幅牵索挂篮 快速施工 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]