The paper is aimed at comparing the results of numerical analyses of underground openings in
competent rock masses like the Carrara Marble (Italy) by considering a real and well documented case
study. More specifically, 3D FEM and DEM analyses were carried out on a rock-mass model interested by
two faults and three sets of discontinuities. The geometrical model is representative of deep underground
openings where spalling-cracks and rock bursts can occur. PLAXIS 3D and 3DEC were used for the
analyses. Intact rock and rock mass characterization of Carrara Marble was inferred from available
technical literature. The analysis results were compared in terms of principal stresses and displacements
in a number of monitoring points around the opening. The main practical interest is to find out a reliable
approach for evaluating the stability of very large openings in a competent rock mass like Carrara marble.
For such a purpose, a number of available in-situ stress measurements were used
