A retaining wall 8 m high with a smooth vertical back retains a clay back fill with C' = 15 kN/m2, φ = 15° and γ = 18 kN/ m3. (Given sin 15° &cong; 0.25). The pressure at the top will, nearly, be equal to-A-35.2 kN/m2B-23.0 kN/m2C-27.6 kN/m2D-11.5 kN/m2-D-11.5 kN/m2

D 11.5 kN/m2 Ans should be B. At top z=0 pa= 2crootka= 2*15*√0.6=23.2kn/sq.m.