________ type of cofferdam is economical at places where rock is available in plenty.
(a) Earth dikes
(b) Sand-bags dikes
(c) Rock-fill cofferdam
(d) Single wall cofferdam
I had been asked this question during an internship interview.
I need to ask this question from Cofferdam and Caisson in chapter Deep Excavations, Pile Foundations and Caisson of Construction & Building Materials