A masonry retaining wall is 1.5 m wide at the top, 3.5 m wide at the base and 6 m high. It is trapezoidal in section and has a vertical face on the earth side. The backfill is level with top. The unit weight of the fill is 16 kN/m³ for the top 3 m and 23 kN/m³ for the rest of the depth. The unit weight of masonary is 23 kN/m³. Verify the total lateral pressure on the wall per metre run and the maximum and minimum pressure intensities of normal pressure at the base. Suppose φ = 30° for both grades of soil.