A general limit equilibrium model for three-dimensional slope stability analysis

Abstract

A generalized model for three-dimensional analysis, using the method of columns, is presented. The model is an extension of the two-dimensional general limit equilibrium formulation. Intercolumn force functions of arbitrary shape can be specified to simulate various directions for the intercolumn resultant forces. A unique feature of the model involves the use of a geostatistical procedure (i.e., the Kriging technique) in modelling the geometry of the slope, the stratigraphy, the potential slip surface, and the pore-water pressure conditions. The technique simplifies the data-input procedure and expedites the column discretization and the factor of safety computations. The shape of the intercolumn force functions was investigated for several slope geometries using a three-dimensional finite element stress analysis. The significance of the intercolumn force functions in three-dimensional stability analyses was also studied. The model was utilized to study a case history involving an open-pit mining failure. The results indicate that the model is able to provide a more realistic simulation of the case history than was possible using a conventional two-dimensional model. Key words : stability analysis, general limit equilibrium, three-dimensional, method of columns, factor of safety.