An efficient strength reduction method for finite element slope stability analysis

The Bisection Method is a common search strategy implemented as part of the shear strength reduction procedure for finite element slope stability analysis. Despite the Bisection Method's simplicity and reliability as a root finding technique, it is generally accepted to achieve slower rates of convergence than many alternatives. The aim of this paper is the description of an efficient method for performing shear strength reduction using root bracketing techniques, specifically for Finite Element slope stability analysis. The False Position (regula falsi) Method enables computationally intensive slope models to be simulated by minimising the total number of solver iterations required to determine the factor of safety. Several finite element models are presented to highlight the applicability of the given methods, with significant savings made (in the order of 50 percent) with respect to two of the most common strength reduction procedures - uniform incrementation and the Bisection Method. In all cases, strong agreement in safety factors is observed between traditional strength reduction methods and the proposed techniques.