A rock toe and a horizontal filter is provided on the downstream base of an earthen dam in order to _________________
(a) prevent piping action in the dam body
(b) prevent piping action in the dam foundation
(c) reduce the seepage quantity by blocking its flow
(d) collect and drain out the seepage flow
I got this question by my college director while I was bunking the class.
This interesting question is from Rock Fill Dams in portion Earthen and Rock Fill Dams of Irrigation Engineering