An Introduction to Cofferdams

Cofferdams play an important part in the construction and repair of structures that are built within water. They are watertight enclosures built within a body of water, or in pairs across, that create a dry environment to work in. They allow for water to be pumped out and excavated dry for full access. Cofferdams are commonly used to construct oil platforms, dams, bridge piers, and other support structures. Read on to explore three main types of cofferdams; cellular, braced and double-walled sheet piled.

Cellular Cofferdams: These cofferdams are essential to the construction of locks, dams, wharfs, bridge piers, and other structures in the marine environment. A common cellular cofferdam is consists of interconnected cells that make up a watertight wall. These soil filled cells offer stability against lateral forces. That wall allows the interior to be dewatered with pumping equipment and for permanent structures to be built in a dry area. In this case, the cofferdam is stable by virtue of its own resistance to lateral forces.

Braced Cofferdams: These types of cofferdams are frequently used in urban areas for the contruction of bridge piers and abutments in relatively shallow water. They’re formed from a single wall of sheet piles that form a square around the excavation site and are driven into the earth. Those piles are braced on the inside and the interior is then dewatered.

Double-walled Sheet Pile Cofferdams: These types of cofferdams are used when the depth of water is high and the area of a construction is expansive. More support is required, and a double walled approach can provide an economical means of dewatering a large area. These cofferdams typically comprise of two rows of sheet piles driven into the earth and connected together by a structural system of rods at one or multiple levels. Granular material like gravel or soil is commonly used to fill the space between the two walls.

Cofferdams perform an essential role in construction and repair of many marine area structures. If you are in need of cofferdam construction pump dewatering services, Thompson Pump is a leading pump manufacturing company dedicated to providing heavy duty, safe and innovative solutions. Experienced application engineers and field personnel are trained to design the most efficient pumping systems for any given construction application. Thompson Pump offer quick response and reliable equipment for your construction dewatering needs. Please visit their website for more information: www.thompsonpump.com.