4. At the front face of a retaining wall, the toe of the wall is 3 metres below ground level. The horizontal component of the active thrust on the wall

is 226 kN per lineal metre, and the vertical component of the load on the base is 423 kN per lineal metre.The soil is sandy and has a density of 1.75 Mg/m³, o'crit =27°. Find the passive resistance against the front of the wall. Calculate the ultimate limit states (ULS) for sliding (angle of internal friction is 20°).