Construction Techniques for Concrete Boxed Cofferdams of Pile Caps of Non-Navigable Bridge of Qingdao Bay Bridge

The concrete boxed cofferdams were used for construction of part of the pile caps of the 45-span non-navigable bridge of Contract 7,Qingdao Bay Bridge.The principal structure of a cofferdam includes the lower part reinforced concrete boxed cofferdam,the upper part breakwater board,lifting and installation system and system transformation elements.The design and construction of the principal structure of the cofferdam are described herewith and the main characteristics and deficiency of the cofferdams used in the process of the construction are summarized as well.