深水裸露坡岩大型高低刃脚双壁钢围堰设计与施工

摘要

深水裸露基岩低桩承台施工常采用水下基坑爆破和双壁钢围堰的设计施工方法，由于承台基础结构形式、承台嵌入岩层深度、河床岩层坡面倾斜度、水深和流速等参数的不同，其设计施工难度差异很大。结合南龙铁路闽江特大桥与合福联络线闽江特大桥双壁钢围堰设计施工实例(以17#墩为例)，介绍在水深流急的裸露陡坡岩石地基条件下，进行先堰后桩低桩承台施工时采用大型高低刃脚加活动插板双壁钢围堰的设计施工方法。%T he design and construction methods of underwater blasting foundation pit and double-wall steel cofferdam are often used in the construction of low-piled platform at bare bedrock in deep water. Due to the different parameters such as the structure form and embedded depth of the platform,the gradient of the slope,the depth and velocity of water,the design and construction are very difficult. Combined with Nanlong railway Minjiang Bridge and Hefu tie-lines of M injiang bridge double-wall steel cofferdam design and construction ( take the pier 17# as an example) ,the paper introduced the bare steep slope rock foundation in the condition of deep water and torrent,the method of first weir after pile construction of low-piled platform with large low edge foot and activity plates was used in double-w all steel cofferdam design and construction.