An Efficient Box Search Method for Limit Equilibrium Method-Based 3D Slope Stability Analysis

When the geometry or the loading conditions deviate from the plane strain idealizations employed in the conventional 2D slope failure analysis, a 3D slope stability analysis would be more appropriate. During a 3D slope stability analysis, it is crucial to use an appropriate and accurate search technique to find the critical failure surface (CFS) associated with the minimum factor of safety (FOS) of any slope. This paper describes the uses of the Scoops-3D software's effective box search method for locating the CFS and minimum FOS while studying three-dimensional slope stability problems. The FOS of the 3D slope has been calculated using Bishop's simplified method (BSM) and the limit equilibrium method (LEM) based on the ordinary method of columns (OCM) and LEM. The digital elevation model (DEM) approach is used to build the slope's 3D geometry. The various parameters, such as normal and shear forces along the slope's slip direction and the slope's longitudinal direction, have been investigated. The results of convergence studies of the FOS values vs. the number of failure surfaces analyzed, failure mass, and failure surface have been reported to show the efficiency of the employed search technique. It is seen that the box search is highly efficient in locating the CFS with sufficient accuracy even when all the points inside the box grid are not included in the search operation.