“…In broad terms the main numerical schemes appropriate for this class of problem include the FEM (Finite Element Method) [10,11,12] in its pure continuum form [13], the Discrete Fracture Network (DFN) geomechanical and continuum flow models [14], the Displacement Discontinuity Method (DDM) geomechanical and flow models [15,16,17], the combined FEM/DEM (Discrete Element Method) [18] technique plus the more recent Extended Finite Element Method (XFEM) [4,19].…”