THREE-DIMENSIONAL SLOPE STABILITY: END EFFECTS.

Common procedures for slope stability analysis are essentially two dimensional (plane strain) despite the fact that observed failure mechanisms in the field possess clear three dimensional characteristics. A review of the few existing analysis procedures which are applicable to three dimensional failure mechanisms revealed some serious shortcomings such as failure to degenerate to known solutions when boundary cases are considered or dependence on constants which are extremely difficult to estimate. Presented is a three dimensional failure mechanism which is obtained through a variational limiting equilibrium approach without arbitrary assumptions. This mechanism consists of the shape of the potential slip surface and the potential direction of slip at each point on this surface. The present work deals with homogeneous and symmetrical slopes which are constrained in the 3rd direction; e. g. a dam in a narrow valley or a trench of finite length. The analysis results are presented in a form of stability charts relating the geometrical parameters of the slope, soil properties, and the 3-D factor of safety.