A 40 degrees slope is excavated to a depth of 10 m is a deep layer of saturated clay of unit weight 20KN / (m^3) the relevant shear strength parameters are c_{u} = 72KN / (m^ 2) and phi u =0. The rock ledge is at a great

A thin clay layer passes through the soil at an angle of 30° behind an 8m high gravity retaining wall. A structure 5m wide, applying a uniform stress of 40kPa to the sandy soil, also acts on this section of soil as shown in Figure 3.1. The properties of the clay are ??=25???, ∅?=0, ?′=0 and ∅′=20°. The sandy soil properties are ?′=0, ∅′=35°, ????=16??/?2, ????=20??/?2, and between the sand and the wall the properties are ?′?=0 and ∅′?=30°. Assuming that failure occurs along the clay layer, use Coulomb’s method to calculate the horizontal force required from the wall in the short term to prevent slip.

(Note:Depth of rock layer is 2m not 12 m.) Q A cut slope was excavated in a saturated clay with a slope angle β = 57 ͦ with the horizontal. Slope failure occurred when the cut reached a depth of 8 m. Previous soil explorations showed that a rock layer was located at a depth of 2 m below the ground surface. Assuming an undrained condition and that ɣsat = 21 kN/m3 : Determine the undrained cohesion of the clay (Fig 3). What was the nature of the critical circle? With reference to the top of the slope, at what distance did the surface of the sliding intersect the bottom of the excavation?

3. The following convergence measurements (U) have been made in a 4.6-m-diameter circular vertical shaft in good quality granitic rock mass (Em = 40 GPa, ν = 0.2): θ (deg) U (mm) 0 2.25 45 2.39 90 1.50 135 1.00 a) Derive the equations that relate convergence to in situ stress. b) The angle θ is measured (clockwise) with respect to the x-axis, which is oriented 30 degrees clockwise from True North. What is the orientation of the maximum principal stress with respect to True North?