Introduction

Stability by strength reduction is a procedure where the factor of safety is obtained by weakening the soil in steps in an elastic-plastic finite element analysis until the slope fails. The factor of safety is deemed to be the factor by which the soil strength needs to be reduced to reach failure (Dawson et al., 1999; Griffiths and Lane, 1999).

This example illustrates how a Strength Reduction stability analysis can be done with SIGMA/W. In addition, the results are discussed in the context of an alternate procedure known as a stress-based stability analysis.