This thesis aims to study the behavior of the Pampa de Pongo open pit mine, situated in Peru, in terms of displacements and safety factors against shear failure. Excavations currently reach depths greater than 900m and the orebody is sectioned by several geological faults that may increase the potential risk of collapse of embankments. The stress x strain analyses were carried out by the finite element method, with two and three dimensional models, considering the existence and the absence of the fault system, to better estimate and understand the influence of these discontinuities in the displacements of the rock mass with the advancement of excavations. This study also investigated the differences in results obtained with two commercial finite element programs for solution of geotechnical problems (Phase2 and Plaxis 2D) since they use different techniques to simulate fractures in continuous media. In the stability analyses, the values of safety factors determined by the finite element method in 2D and 3D simulations were also compared with those calculated by the equilibrium method limit (method of slices). In general, it could be observed that the effects of discontinuities are larger on the horizontal displacement fields and they also tend to decrease the values of safety factors, even below the minimum thresholds recommended by Brazilian Standards.