Graphical and Numerical Methods for Stability Analysis in Surrounding Rock of Underground Excavations, Example of Boukhadra Iron Mine N.E Algeria

Underground mining continues to progress to difficult, complex and deeper levels in order to tackle ascending demand of minerals. These deep mining occurs in a very hard conditions, in which right practice must be implemented in order to overcome the technical and safety challenges and reap economic gains. The redistributed stresses, large deformations and creeping behavior in such environments worried engineers and geoscientific researchers. The working technic in Boukhadra iron mine is based on the sublevels slaughtered, with room, pillar workings and roof behaviour. Based on rock mechanics and geotechnical engineering methods, our research adopted geo-mechanical and numerical approaches to predict the rock mass behaviour in Boukhadra underground mine and to deal its stability problem. The results show that plastic deformations and stress points increasingly in pillars. In zones with low cover, the tensile zones develop at the roof, leading to a progressive rupture giving rise to a droop. In some areas, fractures develop in a rather remarkable way; in this case the breaking of the pillars and collapse can occur generalized and brutal. The stability of room-and-pillar mines does not depend only pillars. It involves the determination of critical factors and limits of mining. Our study demonstrates that the use of scientific and technical achievements, have become a necessity in mining.