Slope stability analysis using strength reduction technique

Abstract

An approach using strength reduction factor (SRF) for finite element analysis, with the provision of a failure criterion, and incorporation of graphical output, to examine the failure zone developed, was used in order to determine slope failure and the corresponding safety factor. The state of the effective stresses in a slope is calculated by the finite element method using eight‐node quadrilateral elements of elastic‐plastic soil with the Drucker‐Prager nonlinear stress‐strain relationship and a nonassociated flow rule. Slope failure occurs when the yield zone spreads over the entire slip surface and the corresponding SRF is the safety factor of the soil slope. The slope failure could be clearly defined and progressive failure was also observed. It should be kept in mind that the critical slip surface is not unique. A narrow yielding zone was developed when the slope started to fail and any slip surface passing through the yield zone could be the failure surface. The factor of safety obtained by the proposed procedure is in good agreement with that determined by Bishop's method.