Answer Happy

The slope shown below is a cross section through part of ahighway slip road. The unit weight of the clay is 20kN/m3 and the drained soil shear strength parameter is:ϕ' = 22°. A trial failure plane has been assumedhaving radius R = 18.460m and an angle (θ= 45°) at the centre of rotation O.
Determine the factor of safety for the assumed failure plane(using the Swedish method of slices), using theinformation provided in the table below, for theentire slope:
(a) Assuming zero pore pressure on the failureplane
(b) Accounting for pore pressure on the failureplane
Slice 1 2 3 4 Width (b: m) LO 1.50 1.50 1.50 1.50 5 1.50 6 1.50 7 1.50 8 0.71 9 Ave height h: m) 0.37 1.04 1.58 1.98 2.22 2.29 2.16 1.90 1.58 0.95 Water table height (hw: m) 0.25 0.70 0.98 1.15 1.16 0.98 0.62 0.18 0.00 Angle (a: °) 3 7 11 12 15 17 22 23 25 3ihw b W (not to scale) 7 8 9