Q3. Determine the total active thrust on the retaining wall shown in the figure below according to the Coulomb theory for the given trial failure plane. The unit weight of the soil is 20 kN/m³; the appropriate shear strength parameters are cu= 10kN/m² and Qu=25°; the angle of friction between the soil and the wall is 200, and the wall adhesion is the same as cu. (Take unit weight of water as 9.8 kN/m²) 8 m 50kN/m 5m- 2m 45° -NOT TO SCALE- Trial failure plane 85° 55°