Cofferdam

Definition

A cofferdam is a watertight enclosure built in or around a body of water, from which water is pumped out to expose the bottom and permit construction work.

Purpose

The purpose of a cofferdam is to provide a dry work area for construction projects that take place below the waterline. By excluding water from the enclosed area, workers can safely build foundations, piers, or other structures.

Examples of Use

• Cofferdams are used in the construction of bridge piers, allowing workers to build the foundations in dry conditions.
• They are utilized during the repair of dams and other water control structures.
• Marine construction projects, such as the building of docks and harbors, often employ cofferdams.

Related Terms

• Sheet Piling: Interlocking steel or concrete sections driven into the ground to form the walls of a cofferdam.
• Dewatering: The process of removing water from the cofferdam to create a dry work area.
• Caisson: A watertight retaining structure used to work on the foundations of a bridge pier or other structure.

Notes

Cofferdams must be carefully designed and constructed to withstand the pressure of the surrounding water and prevent leaks.