13.20 The slope shown in Figure 13.53 has recently failed. A geotechnical investigation indicates the failure surface was as shown. Assuming the failure occurred while undrained conditions prevailed in the slope, back-calculate the value of su. Use the Swedish slip circle method with the cross-section that existed immediately before it failed. Use y = 119 lb/ft³.

A cut is made into a homogeneous soil as depicted in the figure below, at an angle of 60° with the horizontal. Calculate the resisting shear force in kN along the failure plane given that the shear force applied by the overlying soil wedge is 120 kN. The failure plane is at an angle of 40° from the horizontal direction and the ground water level is below this plane. Assume drained conditions for this question.

A level site underlain by fully saturated clays is cut over a few days as shown in the figure below. The water table is located at the ground surface across the site. Determine the resisting

3. For the planar wedge shown below: 22 m Slip surface 39° 28° Calculate the factor of safety against plane failure assuming: p (degree) y (kN/m³) c (kPa) 55 2800 1850 c: cohesion of rock mass; y: unit weight of rock mass; q: friction angle of rock mass