What is the primary purpose of a cofferdam?

• A. To prevent soil erosion
• B. To create a waterproof enclosure for construction work
• C. To aid in concrete curing
• D. To support underground utilities

Answer: (B)

The primary purpose of a cofferdam is to create a waterproof enclosure for construction work. A cofferdam is a temporary structure built to hold back water from an area where construction is occurring, usually in or near a body of water like a river or lake. By providing a dry, work-friendly environment, cofferdams enable construction activities to proceed safely and effectively, such as foundation work for bridges, dams, or other submerged structures.

This specialized structure ensures that workers can access the site without dealing with the challenges posed by water ingress, which can complicate excavation and construction processes. Additionally, cofferdams also protect the construction site from erosion and help manage sedimentation, which further emphasizes their importance in various civil engineering projects.

The other options do relate to environmental and construction processes but do not capture the primary function of a cofferdam as effectively as creating a waterproof enclosure does.