水下无现浇封底混凝土钢-混组合吊箱围堰施工技术  

Construction Techniques for Steel-Concrete Composite Suspension Cofferdam without Cast-in-Situ Bottom Sealing Concrete

作　　者：宁晓冬 杨晨光 NING Xiao-dong;YANG Chen-guang(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1期132-138,共7页Bridge Construction

摘　　要：广东佛山龙翔大桥主航道桥为(118+2×202+93)m连续梁桥,主墩均采用圆端形承台(尺寸为39.25 m×17.5 m×5.0 m)。3号、4号主墩位于水中,均采用无现浇封底混凝土的钢-混组合吊箱围堰施工,围堰主体结构为混凝土底板-钢板桩壁体组合。在围堰施工过程中,混凝土底板及钢壁体在加工场内分块加工并运输至墩位,逐块吊装拼接,减小了施工吊重;钢壁体与混凝土底板采用无嵌固方式进行耦合连接,通过止推块及拉杆的双向限位实现了壁体与底板的耦合及密封;采用智能连续同步千斤顶系统进行围堰下放,解决了下放过程中混凝土底板的开裂问题;通过自闭式软管浇筑少量混凝土封堵护筒环缝,实现了围堰底部密封;利用壁体-底板耦合系统的快速拆除技术,实现了无需水下作业的壁体快速化拆除。The main navigation channel bridge of Longxiang Bridge in Foshan,Guangdong Province is a continuous girder bridge with spans of 118,2×202 and 93 m.All the main piers are mounted on round-cornered pile caps with dimension of 39.25 m by 17.5 m by 5.0 m.The main piers No.3 and No.4 are river piers that were constructed with the aid of the steel-concrete composite cofferdam without case-in-situ bottom sealing concrete.The cofferdam consists of concrete bottom slabs and steel sheet pile walls.During the construction of cofferdam,concrete slabs and steel sheet pile walls were fabricated in segments,transported to the pier sites and assembled segment by segment to reduce the lifting weights.The steel sheet pile walls and concrete slabs were connected in a coupling manner,rather than in a built-in manner.The coupling and sealing of the cofferdam walls and bottom slabs were realized via the two-way displacement restricting function of stoppers and tie rods.The cofferdam was lowered by the intelligent continuous and synchronized jack system,which,at the same time,resolved the cracking problem of the concrete slabs during the lowering of the cofferdam.The annular stitches in the steel casings were concreted via self-closing hoses to realize the sealing of the cofferdam bottom.And the coupled connection of steel sheet pile walls and bottom slabs can be rapidly demolished with ease,and no underwater operation is needed.

关 键 词：连续梁桥 圆端形承台 无封底钢-混组合围堰 装配化施工 基础施工 施工技术 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] U445.556[交通运输工程—道路与铁道工程]