Comparison and Application of Cofferdams for Pile Caps of Non-Navigable Bridge of Qingdao Bay Bridge

The pile caps of the non-navigable bridge of Qingdao Bay Bridge,90 numbers in total,can be classified into Types E,F and G by the sizes of the caps.In the construction of the pile caps,4 kinds of the cofferdams,i.e.the steel sheet pile cofferdam,plug-in sheet pile cofferdam,single-wall steel cofferdam and concrete boxed cofferdam with bottom,were used.The structural design and construction methods for the 4 kinds of the cofferdams are introduced herewith and the cofferdams are compared and analyzed from aspects of the construction time schedule and economy.According to the application of the cofferdams in the field,the single-wall steel cofferdam and the concrete boxed cofferdam with bottom have considerable advantage over the other two kinds of the cofferdams in regard to the construction time schedule and construction cost control.