Question

__________ is useful when depth of water is about 6 metres to 10 meters.

(a) Wood or steel sheeting cofferdam

(b) Ohio river type cofferdam

(c) Rock-filled crib cofferdam

(d) Suspended cofferdam

I had been asked this question in examination.

This interesting question is from Cofferdam and Caisson topic in section Deep Excavations, Pile Foundations and Caisson of Construction & Building Materials

Answer 1

Correct choice is (a) Wood or steel sheeting cofferdam

For explanation: For small and ordinary type of cofferdam, the wooden sheet piles are employed. But when cofferdams are large or where it is not possible to drive guide piles due to more depth of water, the steel sheet piles with suitable bracing are used for the construction of this type of cofferdam.