These are generally used to enclose small foundation sites in water for bridges at a relatively shallow depth. In this type of coffer dams, there is a single row of cantilever sheet piles. The piles are sometimes heavily braced. Joints in the steet piles are properly sealed. This type of coffer dams are suitable for moderate-flow velocities of water and for depth upto 4 m. The depth of penetration below ground surface is about 0.25h for coarse sand and gravels, 0.5h for dine sand and 0.85h for silts, where h is the depth of water. Sometimes single-sheet coffer dams are provided with earth fills on one or both sides to increase the lateral stability. The figure of single sheet pile cofferdam is shown in follow.
(This article comes from CivilEblog editor released)