武汉二七长江大桥中主塔墩基础围堰施工技术

Construction Techniques of Cofferdam for Intermediate Pylon Pier Foundation of Wuhan Erqi Changjiang River Bridge

武汉二七长江大桥通航孔主桥为三塔双索面斜拉桥,中主塔墩位于长江中心航道上,其下部结构基础为18根3.40 m钻孔灌注桩。采用双壁钢吊箱围堰法进行基础施工。钢吊箱围堰在工厂制造,完成后整体滑移下水并浮运至墩位,采用重力锚锭系统进行围堰定位;围堰定位完成后,插打定位钢护筒,将围堰与已经插打完成的钢护筒进行连接形成稳定的钻孔平台,插打剩余钢护筒,进行钻孔桩施工;钻孔桩施工完毕,将围堰下放至围堰封底设计标高,进行围堰清淤、堵漏,用垂直导管法依次浇注封底舱、底隔舱、侧舱封底水下混凝土,按照从两端向中间、从外向内的顺序分块、对称进行施工。

The navigable span main bridge of Wuhan Erqi Changjiang River Bridge is a triple-pylon and double-cable-plane cable-stayed bridge with its intermediate pylon pier located in the central shipping channel of the Changjiang River.The foundation of the pylon pier is made up of 18 nos.of 3.40 m bored piles and was constructed by the double-wall steel boxed cofferdam.The cofferdam was manufactured in shop,launched to river integrally and floated to the pier site where it was positioned by the gravity anchor syst...