Locating Global Critical Slip Surface Using the Morgenstern-Price Method and Optimization Technique

Abstract

This paper presents a method to locate the global critical slip surface for slope profiles with complex geology. In this method, a readily available concise algorithm based on the Morgenstern-Price method is used to efficiently calculate the factor of safety for a slip surface. This algorithm is combined with an optimization technique to search for global critical slip surfaces based on a set of random initial slip surfaces. The proposed method is applied to analyze three example problems involving slope profiles with various degrees of complexity. This study indicates that the proposed global search strategy can locate the global critical slip surface regardless of the initial slip surface for slope profiles with low to moderate complexity. For more complex geologic slope profiles, however, the proposed search strategy may only be able to identify locally critical slip surfaces depending on the initial slip surface. To ensure that the global critical slip surfaces are identified, more random initial slip surfaces need to be considered. A sound engineering judgment may be combined with the global search algorithm presented in this study to locate global critical slip surfaces more efficiently.