Surcharge loading required to be placed on the horizontal backfill of a smooth retaining vertical wall so as to completely eliminate tensile crack is:
(A) $2 c$
(B) $2 c k_{2}$
(C) $2 c \sqrt{k_{a}}$
(D) $2 c / \sqrt{k_{a}}$
Surcharge loading required to be placed on the horizontal backfill of a smooth retaining vertical wall so as to completely eliminate tensile crack is:
(A) $2 c$
(B) $2 c k_{2}$
(C) $2 c \sqrt{k_{a}}$
(D) $2 c / \sqrt{k_{a}}$