Stability of Foundation Pits Protected by Coffer Dams

During construction of underground structures and foundation rafts or footing, excavation are made to house them. The sides of excavated area are often protected by single wall coffer dams. The working area is also kept dry by removing the water flowing in it. In order to estimate the influence of the flowing water on the stability of the coffer dam and the foundation pit, use of flow nets are often made, which demands lot of design office time. In this paper an analytical method is proposed and the results are presented in graphs for ready use of designers.