Graving Dock No. 3 Emergency Repair - Groton, Conn.
In May 2004, a sheetpile cell at the General Dynamics Electric Boat facility catastrophically ruptured during dewatering operations. The sheetpile cell, located at Graving Dock #3, was integral in keeping water from the Thames River out of the dock and providing structural support for the perimeter work platforms.
Kiewit completed a $22 million emergency contract to provide structural repairs to the dock. New sheetpile was driven inside the affected cell, cutting off the loss of cell fill into the graving dock. Crews jet grouted columns inside the cell to stabilize it and allow for removal of the temporary stabilizing fill. The jet grouted columns strengthened the cell, allowing it to handle the loading induced by dewatering. After installation of the jet grout columns, the project team achieved a major schedule milestone when they dewatered the graving dock and removed the stabilization fill by January 5, 2005. Crews also installed geotechnical instrumentation to monitor movement and ground water during all aspects of the work.
The project was completed in April 2005. The success of the project led General Dynamics to award Kiewit a $32 million follow-on contract to provide permanent repairs to the dock.