Strength Reduction Method for Slope Stability Analysis Based on a Dual Factoring Strategy

A shear strength reduction method based on a dual factoring strategy was considered in which cohesion and the coefficient of internal friction were each reduced by a different factor. By using a strength reduction path introduced in the present study, series of numerical tests were conducted to bring the slope into different states of critical equilibrium through which definitions of the factor of safety and the strength reduction path adopted in some preceding studies were evaluated. This strategy was found to be more conservative than the traditional shear strength reduction method. Generally, the factor of safety defined in the limit equilibrium method should be adopted, and the most probable strength reduction path under the principle of the shortest path could be an effective approach to obtain the minimum value of the factor of safety directly. To implement this strategy, a mathematical model based on limit analysis solutions is proposed to describe the shear strength components of a slope under different critical equilibrium states, and a general computational procedure is outlined. (c) 2018 American Society of Civil Engineers.