Pump out water from inside the cofferdam.
Progressively install internal reinforcements as needed.
Dig the trench to allow the leaks to run to one location.
Place rock fill as a leveling and support course.
Mud
This is a simple form of cofferdam suitable for shallow water areas with low current velocity, where a sloping earthen embankment is constructed around the area to be enclosed. The bank should be a combination of clay and sand or clay and gravel.
Rock fill
If the water to be retained is not shallow enough for an iran email list earthen cofferdam, stones or rubble may be used instead. The stones are built into the required shape of the cofferdam, and the gaps are filled with soil, gravel or stone chips.
Single wall
This type of cofferdam is most suitable when the area to be enclosed is particularly small and the water is at a deeper level, approximately 4-6 m. Guide piles made of timber are driven into the ground and reinforcements are built in before the sheet piles are set in place and secured to the reinforcement with bolts.
Double wall chests
Single-walled chests become unfeasible as larger areas are required in deeper water, so double-walled chests are sometimes needed. Two walls are built with a gap between them, the thickness of which depends on the depth of the water.
