13.17 Calculate the factor of safety for a filling landfill shown in Figure 13.25 against possible mass movement. Use a two-wedge analysis and the following information: Interface friction angle of bottom liner, \delta _(p)=18\deg , Interface residual friction angle of side slope liner, \delta _(A)=10\deg ; Friction angle of solid waste, \phi _(s)=33\deg ; Waste unit weight =70l(b)/(f)t^(3); Landfill subgrade is 2%[50(H):1(V)],\theta =1.15\deg ; Side slope angle, \beta =18.4\deg [3(H):1(V)]; Waste filling slope is ; Height of side slope is 50 feet; Distance between the top edge of waste and the top edge of side slope is 50 feet. If the waste filling slope is changed to 33%[3(H):1(V)], recalculate the factor of safety