Construction of Double-Wall Steel Cofferdams for Hengyang Xiangjiang River Bridge on Wuhan-Guangzhou Passenger Dedicated Railway

The double-wall steel cofferdams were used for Piers No.54～58 of Hengyang Xiangjiang River Bridge on Wuhan-Guangzhou Passenger Dedicated Railway.After the cofferdams were positioned,sunk to the designed elevation,the bottoms of the cofferdams were sealed with concrete and the construction of foundations of the piers was then carried out.In this paper,the design of the cofferdams,the principles and methods for assembling,floating,positioning and sinking of the cofferdams are dealt with.