Slope stability in the Trenton limestone of a Montreal area quarry

CIM Bulletin, Vol. 76, No. 856, 1983

JOHN E. UDD, At time of writing, Associate Professor, Department of Mining and Metallurgical Engineering, McGill University, Montreal, Quebec, MARC C. BETOURNAY, Rock Mechanics Research Officer, CANMET, EMR Canada, Ottawa, Ontario

In this study, the authors investigated the stabilities of slopes cut predominantly into Trenton limestone in a large quarry in the Montreal region. Analyses of the bench and pit walls indicated that small-scale toppling, ravelling, and wedge failures are the most likely modes of instabilities. Because most of the joints dip steeply, however, the conclusion was made that relatively high walls could probably be justified. The field investigations were supplemented with the determinations of the shearing strengths of artificial discontinuities that were cut into samples of the limestone. The properties of a fine-grained limestone were found to be influenced very much by the magnitudes of the loads that were applied, while the properties of a crystalline limestone were found to be much less, or not load-dependent. The study is one of a number that are being conducted in this area.

Keywords: Rock mechanics, slope stability, Trenton limestone, Montreal, Structural analysis, Failure analysis, Quarries, Geology.