Mathematics · Soil Mechanics

A vertical retaining wall is 10 m high. It retains two different soils: from 0 to 5 m depth (c = 0, φ = 30°, and γ = 18 kN/m3) and from 5 m to 10 m depth (c = 0, φ = 30°, and γ = 20 kN/m3). Find the ratio of passive earth pressures just above and below the boundary at 5 m depth.