Numerical methods in the stability analysis of slopes

Abstract

Traditionally, the safety of embankment slopes has been determined using limit equilibrium methods. This analysis provides the engineer with a factor of safety against failure but does nothing in terms of determining what displacements may occur or what state of stress exists. Another analysis tool is the finite element analysis which enables the use of various material models to determine the stresses and displacements. Often a limit equilibrium analysis yields a factor of safety that is satisfactory in terms of catastrophic failure but is unsatisfactory in terms of lateral movement because of sensitive structures bordering the embankment. This paper presents a numerical procedure for slope analysis that combines the finite element analysis using a nonlinear material model with the limit equilibrium analysis for the determination of the factor of safety. Sensitivity studies are presented showing the results of various slopes using the simplified Bishop Method, linear, and nonlinear material models. In addition, advantages in using the finite element analysis for slope analysis are shown.