FINITE ELEMENT ANALYSIS OF SLOPE STABILITY- BY NEW NUMERICAL PROCEDURE (SDIM)

Abstract

The assessment of slope stability factor by a finite element analysis using the shear strength reduction method (SRM) is one of the most powerful methods that have been proposed as a competitive to the conventional limit equilibrium methods (LEM) in the last two decades . Although the SRM enjoys several advantages, it owns unfortunately many shortcomings. As an alternative, a new finite element approach called stress deviator increasing method (SDIM) is proposed in this paper. The new approach assesses the slope stability by incrementally increasing the mobilized principal stress deviator until the soil failure is reached. The incremental increasing of the factor that controls the expansion of principal stress Mohr’s circles in the SDIM, follows the reverse path as that of reducing factor in the SRM. The numerical procedure is based then on a rigorous formulation as it preserves the definition of the safety factor consistent with that of LEM and maintains the progressive development of the shear stress on same plane on which the shear strength will occur at failure. The proposed method deals with the actual material by using the real strength parameters (𝑐, 𝜙)and 𝜓 rather than those reduced by a factor. The results of SDIM encoded in a computer code called 𝑆 𝐷𝐼𝑁𝐴 were thoroughly assessed against those of both SRM and LEM