(Solved): Cross-section of a dam is shown in the figure. The side slope of dam section at the upstream side ...

Cross-section of a dam is shown in the figure. The side slope of dam section at the upstream side is $$2.5\mathrm{H}:1\mathrm{V}$$. Stability analysis of the dam section is required to be performed using an infinite slope analysis for a rapid drawdown of $$70\mathrm{ft}$$. The values of c', d, $$?,?$$ ' were $$0\mathrm{psf},1100\mathrm{psf}$$, $$23^0$$, and $$37^{?}$$, respectively. The saturated unit weight of the dam material was 125 pcf. Please calculate the factor of safety of the dam slope (at the location shown with open circle) immediately after the rapid drawdown.