Résumé: MR system and numerical modeling for mining underground excavation design of the Djebel El Ouahch tunnel, in Constantine (Algeria). The geological and geotechnical character-ization of the rock mass is important for the design of underground mining excavations. In this article, we present the results of the RMR characterization of the rock mass and the numerical modeling by the finite element method (FEM), under the conditions of the Djebel El Ouahch tunnel, Constantine (Algeria). The RMR system is a useful tool for characterization of the rock mass quality and establishing the appropriate support system. For poor rock (Class IV), the excavation should be top heading and bench 1.0 m–1.5 m advance in top heading. Support should be installed concurrently with excavation, 10 m from face. Rock bolting should be systematic with 4 m–5 m long, spaced 1.5 m–1.5 m in the crown and walls with wire mesh, Shotcrete of 100 m-150 mm in the crown and 100 mm in sides. The steel sets should be light to medium ribs spaced 1.5 m only when required. The rock mass consists of generally poor rocks with average stand-up time of 10 hours for 2.5 m span with mass cohesion ranges between 100 kPa–200 kPa and rock mass friction angle ranges from 15 to 35. The FEM project due to its precision calculates the safety factor and evaluates the principal deformations and displacements of the rocks mass. The originality of this work lies in the use of two different approaches, the RMR system and numerical method (FEM) for analyzing the quality and evaluation of the …