Which of the following conduits are commonly used in highway or railway culverts?
(a) Positive/Negative projecting conduits
(b) Negative projecting conduits
(c) Ditch conduits
(d) All of the mentioned
I have been asked this question during a job interview.
My question is taken from Classes of Underground Conduits topic in division Shafts, Tunnels and Conduits of Geotechnical Engineering II