2014年9月上第43卷第17期
DOI :10. 7672/sgjs2014170049
施工技术
CONSTRUCTION TECHNOLOGY
新白沙沱长江特大桥3号墩双壁钢套箱围堰施工技术
宁洪伟，李艳哲，贾为民，张成军
（中铁大桥局集团第一工程有限公司，河南郑州450053）
【摘要】渝黔铁路新白沙沱长江特大桥主塔墩3号墩位于主河槽通航航道上，水深15~20m，河床地形条件复杂，部分为水下爆破区域，存在卵石覆盖层、倾斜光板岩，突石等多种情况；基础施工采取先平台后围堰的方案，且钻孔与围堰同步双层作业。3号墩桩基础为36根直径3.2m的钻孔桩，承台施工采用双壁钢套箱围堰方案。对该套箱围
堰的组拼、下沉、定位、堵漏、抛填等施工工序中应用的工艺、技术措施进行了分析总结。【关键词］桥梁工程；斜拉桥；钢套箱围堰；堵漏；施工技术
［中图分类号］U445.55
【文献标识码］A
［文章编号】1002-8498(2014)17-0049-04
Construction Technology of Double-wall Steel Boxed Cofferdam of the
No.3 Pier for New Baishatuo Yangtze River Bridge
Ning Hongwei,LiYanzhe,JiaWeimin,Zhang Chengjun
( The First Engineering Co. , Lid. , China Railay Major Bridge Engineering Group, Zhengzhou, He' nan 450053, China) Abstract:The No.3 main tower pier of New Baishatuo Yangtze River Bridge in Chongqing-Guiyang Railway is positioned on the navigation channel of the main river channel. The depth of water is about 15 to 20 m, the bed topography condition is complicated that a part of the bed topography is underwater blasting area, and several situations of covered pebble bed, inclined bare rock, raised rocks are existed. The foundation construction adopts the scheme of starting with the construction of the platform and then the cofferdam, and drilling and cofferdam are operated synchronously on two decks. The pile foundation of the No. 3 pier is 36 drilled piles with the diameter of 3. 2 m, and the cushion cap construction adopts the double-walled steel boxed cofferdam scheme. The technologies and technical measures applied to the construction procedures of assembling, sinking, positioning, leaking stoppage, dumping filling are analyzed and summarized.
Key words : bridges ; cable stayed bridges ; steel boxed cofferdams; plugging; construction
工程概况
渝黔铁路新白沙沱长江特大桥主桥为钢桁梁斜拉桥，设计里程为D1K17+092.55—D1K18+ 014.30，孔跨布置为（81+162+432+162+81）m，分上、下两层桥面布置。上层为4线铁路客运专线，设计时速200km；下层为双线铁路货车线，设计时速 120km。该斜拉桥是世界上首座双层6线钢桁梁铁路斜拉桥，也是世界上延米荷载最重的钢桁梁斜拉桥。主桥结构如图1所示。
3号墩为贵阳侧主塔墩，位于主河槽通航航道上，为H形塔，塔高192m，3号墩基础设计为36根*中铁大桥局科研项目（桥经[2013】148号）：双层六线大跨度重载铁路斜拉桥建造技术研究
［作者简介］宁洪伟，高级工程师，E-mail：nhw_2002@163.com［收稿日期］2014-05-16
545810016200
高品的品高的 350
43 200
16200810045
49
贵附(长沙)
图1新白沙沱长江特大桥主桥立面布置（单位：cm） Fig.1 Evaluation arrangement of the main bridge of New Baishatuo Yangtze River Bridge( unit : cm)
Φ3.2m钻孔灌注桩，设计桩长65~79m，4×9行列式布置，纵桥向间距8.5m，横桥向间距7.2m。承台结构尺寸为67.4m×31.3m（含圆弧端面），厚