Technology Research of Underwater Repair on Dam Upstream Face

For any of a large reservoir, it will involve enormous consequences of economic, social and environmental protection to vent reservoir to leakage repair of upstream face of the dam. Thus, in the case of without venting reservoir, it is indeed a very challenging new topic how to repair the dam upstream face. The construction technology of the floating arch cofferdam is first surrounding part of the dam surface without venting the reservoir, which can create the "dry job" environments to repair cracks on concrete surface of dam. After completion of the construction, the water is discharged in the cavity of the arch cofferdam, and the arch cofferdam can automatically rise to float in the water. The floating arch cofferdam is towed to the next construction unit by tugboat, and is water-filled, sank, placed, water sealed, drained the stagnant water inside the cofferdam to create another "dry" environment for construction. Aiming to the most severely freezing-thaw damaged parts for Man tai city dam, a steel tube cofferdam of semi- round is constructed. We have no submariners’ assistance for this test, but arch cofferdam floating underwater install still be finished. When sealing is done, the water within the cofferdam is pulled out, and the "Dry work" environment is formed for construction.