SEISMIC STABILITY ANALYSIS OF THREE DIMENSIONAL SLOPES USING ACCEPTABLE STRESS FIELDS

Presented is a method of three-dimensional stability analysis of slopes due to earthquake forces based on the Lower-bound theorem of the limit analysis approach. The method’s aim is to determine the factor of safety of such slopes using numerical linear finite element and lower bound limit analysis to produce seismic stability charts for three dimensional (3D) homogeneous slopes. The rigorous limit analysis results in this paper together with results of other researchers were found to bracket the slope stability number and therefore can be used to benchmark for solutions from other methods. It was found that using a two dimensional (2D) analysis to analyze a 3D problem will lead to a significant difference in the factors of safety depending on the slope geometries. Numerical 3D seismic results of the proposed algorithm are presented in the form of some dimensionless graphs which can be a convenient tool to be used by practicing engineers to estimate the initial stability for excavated or man-made slopes.