蒙华铁路汉江特大桥钢管桩围堰设计及施工工艺研究

Construction Technology Research on Designing Steel Pipe Pile Cofferdam for Hanjiang Extra-large Bridge of Inner Mongolia-Jiangxi Railway

蒙华铁路汉江特大桥主跨采用(72+ 116 +248+ 116 +72)m五跨部分斜拉桥跨越汉江主航道,主墩基础施工采用锁口钢管桩围堰.锁口钢管桩围堰在砂类土、黏性土、碎石土等易于插打的软质土体上应用较多,在超厚砂卵石地质条件下深水基础施工中一般采用双壁钢围堰施工,而采用锁口钢管桩围堰施工在国内尚属首次.本文结合该工程特点对围堰进行设计研究,重点介绍了“CT”型锁口钢管桩围堰的重难点施工工艺,为以后同类型深水施工提供了借鉴和指导作用.

The main span of Hanjiang Extra-large Bridge in Inner Mongolia—Jiangxi Railway adopts five—span cable—stayed bridge with a length of(72+1 16+248+1 16+72)m to cross the main channel of Hanjiang River,and the main pier foundation is constructed by locking steel pipe pile cofferdam.Locking steel pile cofferdam is widely applied in soft soil mass such as sandy soil,cohesive soil and gravel soil,and the double—wall steel cofferdam is generally used in deep water foundation construction under the conditions of ultra—thick sandy gravel geology.The construction of locking steel pipe pile cofferdam is first applied in China.This paper studies the cofferdam design combining with the characteristics of the project,and introduces emphatically the key construction technology of“CT”type locking steel pipe pile cofferdam.It could provide a reference for deep water construction of similar projects in the future.