Soil stability analysis
A finite-element method is used to analyze the slope stability problem and to examine the effect of soil militancy on the stability of slopes. It is found that soil militancy has a significant effect on the stability of slopes, and the higher values of dilation angle lead to larger stability numbers. Therefore, the stability numbers obtained from limit analyses (lower/upper bound solutions) are not conservative for granular soils that exhibit a stretching angle smaller than a soil's friction angle. The factor of safety equations are written in the same form, knowing whether moment and (or) force equilibrium is explicitly satisfied. The normal force equation is of the same form for all methods with the exception of the conventional method. The method of handling the inter slice forces differentiates the normal force equations. A new derivation for the Morgenstern–Price method is presented and is called the 'best-fit regression' solution. It involves the independent solution of the force and moment equilibrium factors of safety for various values of λ. The best-fit regression solution gives the same factor of safety as the 'Newton–Rap son' solution.