Caisson Sinking
The caisson sinking method is one way to construct underground concrete structures, such as bridge piers, intake structures, pump houses and dumper pits, in soils with a high water table. In this method, a caisson is constructed on the unexcavated site, with the caisson comprising only the walls of the final structure. Then excavating is conducted inside the walls so that the caisson sinks under its own weight.