A masonry retaining wall of trapezoidal section with the vertical face on the earth side is 1.5 m wide at the top and 3.5 m wide at the base and is 5.0 m high. It retains a sand fill sloping at 2 horizontal to 1 vertical. The unit weight of sand is 18 kN/m2 and φ = 30°.
Determine the maximum and minimum pressure at the base of the wall supposes the unit weight of masonry as 23 kN/m3.