Launching and Floating of Steel Boxed Cofferdam for Main Pier Pile Cap of Bridge Part of Shanghai Changjiang River Tunnel and Bridge

This paper presents the launching and floating of steel boxed cofferdam for construction of pile cap of main pier foundation of the main navigable span of Shanghai Changjiang River Bridge in the Shanghai Changjiang River Tunnel and Bridge Project,currently the largest combined project of tunnel and bridge under construction in the world.The steel boxed cofferdam is designed as a structure combining both ship collision protection device and construction cofferdam,and is fabricated in workshop,launched to river in integrity by sliding and floated to the pier site where it will be hoisted and installed.The size of the cofferdam is 76.4 m×41.4 m×10 m,and is also the largest cofferdam for similar bridge works at present.