Method of Slices

In this method, failure mass is subdivided into vertical slices and factor of safety is determined based on force equilibrium equations. A circular arc slip surface and a rotational failure mode is often used in this method. The resisting and the driving forces are calculated for each slice and then summed to obtain factor of safety of the slope. Factor of safety can be calculating the resisting forces to driving forces for each slice and then summed to obtain factor of safety. However, this method involves more unknowns than equilibrium equations in the method of slices. Consequently, an assumption is to be made concerning interslice forces. In ordinary method of slices, resultant of interslice forces is parallel to average inclination of slice, α. Bishop simplified, Janbu simplified, Janbu generalized, Spencer method and Morgenstern Price method are other methods of slices. Because of the tedious nature of calculations, computer programs are routinely used to perform the pseudostatic slope stability analysis using the method of slices.