Single-Walled Cofferdam
This type of cofferdam is preferred when the depth of the water is more than 6m and area of construction is less. Usually this is used in construction of bridges.
Wooden or timber sheets are driven into the river bed on the perimeter of the area of construction. On the inside steel or iron sheets are driven into the river bed. This inside sheets are placed at equal distance with the help of wales which are bolted to both sheets for either sides.
To improve the stability of this types of dam, half-filled bags of sand are placed on the both side of the walls. The water from the inside is pumped out and the construction process is undertaken.
