This work aims to verify the influence of the stress field changing around an excavation in a jointed rock mass, noticing the fracture closure and the hydraulic conductivity decrease in the region surrounding the excavation. At first, the basic characteristics that should be considered in jointed rock masses analyses are presented, pointing out the potential effects caused by excavations in such materials. A brief literature review presents some types of numerical analysis techniques available for discontinuous medium modeling, focusing on the discrete elements methods and, specifically, in the distinct element method (DEM), applied in the UDEC software by Itasca Consulting Group Inc., which was utilized in this work. The simulations make use of a hydromechanical coupling, being the rock mass represented by an assembly of blocks. The water flow takes place among the discontinuities, which are treated as blocks’ boundaries. A hypothetical model was used for modeling validation by comparison with analytical solutions from the literature. Besides that, it was accomplished a real case study of two tunnels located at an important road in Rio de Janeiro city. The parametric analyses of the problem show the influence of changing some important variables in this type of phenomenon. At last, all the results have been discussed, with final considerations and future works suggestions.