Design and Analysis of Potable/Medium Size Cofferdam

This paper presents the detailed description of the multipurpose and cost-effective cofferdam. It contains the forces acting on cofferdam, factors governing its design criteria, various construction techniques, design and analysis of a sheet pile cofferdam. A cofferdam is a temporary structure designed to keep soil and water out of the excavation in which some permanent structure (like bridge piers) is built. When construction takes place below the water level, a cofferdam provides a dry work environment to workers working inside it. Sheet piling is done around the work site, and seal concrete is placed into the bottom to prevent seepage of water from underneath of the sheet piling, and then the water is pumped out. This paper also contains the techniques to install sand filtration bed inside the cofferdam to purify river water.