One common method is the Bishop simplified method of slices (Bishop 1955). This method is
one of several used by Hoek and Bray (1981) to produce series of slope stability charts for circular failure. A limiting equilibrium condition for the development of a tensile crack can be included with the circular failure, as well as the influence of water pressure due to the presence of a phreatic surface in the slope. The charts developed by Hoek and Bray can be used to determine the location of the critical failure circle and tension crack, and find the associated factor of safety for stability
of the slope.