Application of numerical methods to slope stability analysis

Two classes of numerical approaches are considered for the stability analysis of slopes under static conditions: a) the limit equilibrium procedures based on the assumption of rigid, perfectly plastic material behaviour, and b) the elasto-plastic approaches. The methods belonging to the fIrst group provide only an estimation of the collapse load for the slope, while those of the second group are able to evaluate the progressive deformation of the soil/rock mass, and the variation of effective and neutral stresses, up to failure. Some applications ofthese methods to some engineering problems and to some case histories are discussed. After describing an application of limiting equilibrium methods to the analysis of a reinforced earth wall, the discussion is focused on the elasto-plastic finite element approaches. In particular, the evaluation ofthe in situ state of stress, which represents the starting point of the non-linear calculations, and the choice of the constitutive model for the soiVrock mass are discussed. Some comments are finally presented on the effectiveness of the two methods of analysis.