望东长江公路大桥南主墩异型钢围堰施工关键技术  

Key Techniques for Construction of Irregular Shape Steel Cofferdam for South Main Pier of Wangdong Changjiang River Highway Bridge

作　　者：尤吉[1] 房涛[1] 车承志[1] 

机构地区：[1]安徽省高速公路控股集团有限公司大桥建设管理处,安徽合肥230088

出　　处：《桥梁建设》2013年第5期117-122,共6页Bridge Construction

摘　　要：望东长江公路大桥主桥为(78+228+638+228+78)m的组合梁斜拉桥,主梁采用PK型分离双箱形式,大桥南主墩基础为高桩承台结构,采用钻孔灌注桩基础。南主墩基础采用高低刃脚异型钢围堰施工,钢围堰全长50.4m,宽28.4m,钢围堰在高度方向分为2层。钢围堰在工厂制造、拼装成型后,利用气囊法下水,采用"卧倒浮运"方案浮运至墩位处,利用800t浮吊辅助钢围堰实现整体翻转就位;钢围堰定位后,利用水泵向每个隔舱内均匀、对称注水,使钢围堰刃脚快速着床;在钢围堰钢箱内设置6根锚桩,并分3层浇注封底混凝土。该桥钢围堰顺利下沉到位,经检测钢围堰最大平面偏差为98mm,最大垂直度偏差为1/800。The main bridge of Wangdong Changjiang River Highway Bridge is a composite girder cable-stayed bridge with span arrangement （78＋228＋638＋228＋78） m.The main girder of the bridge is of the separated double boxes of the Pasco-Kennewick Bridge type and the foundation for the south main pier is of the bored piles and elevated pile cap structure.The foundation is constructed by the irregular shape steel cofferdam with unequal height cutting edges.The total length of the cofferdam is 50.4 m,the width is 28.4 m and in the direction of the height,the cofferdam is composed of two lifts.The cofferdam is manufactured in workshop and at the time the cofferdam is well assembled,it is launched to the river by the air bag method,floated to pier site by the scheme of ＂lying-down floating＂ and is integrally turned over in place at the pier site by the 800 t floating crane.After the cofferdam is positioned,the bulkheads of the cofferdam are pumped with water uniformly and symmetrically to make the cutting edges of the cofferdam quickly cut into the riverbed.In the cofferdam,6 anchor piles are arranged and the base sealing concrete for the cofferdam is cast in 3 layers.The cofferdam of the bridge is finally smoothly sunk down in place and through the inspection,the maximum plan offsetting of the cofferdam is 98 mm while the maximum vertical offsetting is 1/800.

关 键 词：斜拉桥 桩基础 承台 钢围堰 关键技术 桥梁施工 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.55[交通运输工程—道路与铁道工程]