Etude de la stabilite des souterrains peu profonds par analyse a la rupture generalisee: Effets des regles d'elaboration des modeles

This study makes use of a stability analysis method which is, in fact, a generalization of conventional limit equilibrium methods and takes advantage of linear programming to solve the mathematical indetermination problem that always characterizes such methods. The latter designated by MAREP (Methode generale d'Analyse a la Rupture de l'Ecole Polytechnique), enables to establish two limits (lower and upper) in which lies the real solution, without having to state unverified hypothesis.; The method requires the elaboration of models that are submitted to stability analysis. The objective of this memoir is to precise some of the rules regarding models elaboration.; As to restrict the required work within acceptable limits, it has been initially decided to proceed with three given sets of discontinuities (horizontal, vertical and dipping at 45{dollar}spcirc{dollar}) and with a given excavation span.; The stability analysis results indicate that the method yields a more or less constant safety factor with models possessing a constant excavation span/block size ratio. Moreover, the results show that the larger are the blocks, the smaller are the safety factors, all other variables being kept constant, and to make sure the zone of influence of the excavation is smaller than the model, the latter should include two (2) columns of elements on both sides of the opening and three rows of elements above the opening. These model dimensions are not affected by the cohesion of the discontinuities when no instability occurs. Effects of the dip of the third set of discontinuities as well as of a fourth set on the analysis results are reported.; To give an idea of how MAREP could be used in practice, three shallow mining underground opening located in northwestern Quebec, are preliminarily modelled and some of the potential instability patterns are analysed. (Abstract shortened by UMI.)...