Underground mining operations are a very problematic task, especially in poor geotechnical conditions. The right choice of excavation and support techniques leads to adequate and secure mining operations. This should ensure the overall stability of the underground mine with the best productivity and stability performance. In this paper, an empirical model for obtaining support systems for underground galleries was applied. Then, a numerical model for the evaluation of the performance of support measures for rock masses in the Boukhadra iron mine was introduced. Extensive field and laboratory tests were performed to obtain geological, geotechnical, and mechanical data on the entire geologic formations of the (1105 m) level. The performance of the design is supported by the selection of a common support plan between RMR, Q, and UBC systems for each geotechnical unit. Therefore, the rock masses classification based on the geo-mechanical model has determined the suitable support systems. The finite element model (FEM) was used for the analysis of rock mass behaviour, displacements, stress, and plastic point distribution. The results permit the optimization of the plastic zone thickness around the gallery. The outcomes of this study could improve the stability of the mine by choosing the right direction of excavation in consideration to the direction of the discontinuity planes. In order to choose between the current and the recommended mining operations, an equivalent calculation sequence was verified. Our study demonstrated that the consideration of discontinuity sets in the orientation of excavation highly improves the mining conditions with or without support.

In the two last decades, extraction and use procedures of natural fibers have known an important increase for the reinforcement of composite materials called 'Bi-composites'. This category of fibers possesses a lot of advantages upon those traditional synthetic such as: Abundantly available, reduced cost, lightness and satisfactory specific performances. The current study has the aim of characterizing a new hybrid laminate made up of 4 plies; the upper and lower ones are reinforced with glass bidirectional fabrics while the two central ones are reinforced with natural Jute woven fabrics. The main idea of this work is to preserve sufficient mechanical characteristics by reinforcing the most solicited layers with glass fabric and, in the same time, to ensure an economy and a reduced weight through the reinforcement of the intermediary layers by Jute fabrics. The mechanical characterization was carried out by two kinds of static trials: uniaxial tensile test, three points bending and ILSS tests in order to compare the mechanical properties of this composite laminate with those of a four layers totally glass reinforced laminate. The mechanical trials have given us characteristics, values of the hybrid laminate superior than those of the synthetically reinforced laminate in terms of Flexion and ILSS Strengths but lower in terms of tensile strength. And yet, performances obtained with hybrid Jute/ Glass reinforced laminates allow a prediction of actual perspectives for substituting glass fiber by others natural for semi-structural moderately loaded elements applications to combine performance and economy.