广州明珠湾大桥主墩吊箱围堰定位施工技术  

Positioning Techniques for Suspended Steel Box Cofferdam of Main Pier of Mingzhu Bay Bridge in Guangzhou

作　　者：梁新礼 LIANG Xin-li(Nanfang Engineering Co. ,Ltd. ,China Railway Construction Bridge Engineering Bureau Group,Guangzhou 510850,China)

机构地区：[1]中铁建大桥工程局集团南方工程有限公司,广东广州510850

出　　处：《桥梁建设》2021年第6期139-144,共6页Bridge Construction

基　　金：国家自然科学基金项目(51268031)。

摘　　要：广州明珠湾大桥主桥为(96+164+436+164+96+60)m中承式三主桁钢桁拱桥,该桥27号主墩采用25根直径2.5 m钻孔桩基础、高桩承台,承台尺寸56.5 m(横桥向)×17.5 m(顺桥向)×5.5 m(高)、底标高-2.84 m,桥位处于往复流环境下。27号主墩基础采用双壁钢吊箱围堰兼做钻孔平台方案施工。围堰加工后采用气囊法下水,浮运至墩位处定位、下沉、挂桩,在围堰上铺设钢平台作为钻孔平台;然后进行桩基施工,桩基施工后拆除围堰上铺设的平台;最后进行围堰封底、抽水、承台施工。在围堰定位时,采用靠墩+定位船+重锚定位系统进行施工,其中靠墩布置在围堰上游侧,定位船布置在下游侧,重锚布置在大、小里程方向。围堰定位后,其纵、横向最大偏差分别为30 mm、20 mm,倾斜度2‰,满足设计要求。The main bridge of Mingzhu Bay Bridge in Guangzhou is a half-through steel truss arch bridge with six spans of 96,164,436,164,96 and 60 m.The arch consists of three lateral trusses.The main pier No.27 is mounted on a pile cap of dimension of 56.5 m(along bridge width)by 17.5 m(along bridge length)by 5.5 m(depth),and the base elevation of the pile cap is measured-2.84 m.The foundation of the pier is composed of 25 bored piles of 2.5 m diameter.Due to that the bridge is under the impact of rectilinear currents,a double-walled suspension steel box cofferdam was utilized to facilitate the construction of the bored pile foundation.After taking shape,the cofferdam was launched into water by the air bag method,floated to the pier site,positioned and sunk.Then the construction of the piles began.A steel platform was established on the top of the cofferdam to serve as the borehole drilling platform.When the construction of pile foundation was completed,the platform on the cofferdam was demolished,the base of the cofferdam was sealed,water inside the cofferdam was pumped out and the construction of the pile cap began.Dolphins,positioning barges and heavy anchor positioning system were used for cofferdam positioning.The Dolphins were arranged on the upstream side,the positioning barges were arranged on the downstream side,and the heavy anchors were arranged along the bridge axis.After positioning,the maximum longitudinal and transverse deviations were 30 mm and 20 mm,respectively,and the inclination of the cofferdam was at 2‰,meeting the design requirements.

关 键 词：中承式拱桥 三主桁钢桁拱 双壁钢吊箱围堰 定位系统 靠墩 定位船 重锚 施工技术 

分 类 号：U448.224[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]