Practical rock engineering stope design case histories from Noranda Minerals Inc.

CIM Bulletin, Vol. 82, No. 927, 1989

W.F. Bawden, Queen's University, G. Sauriol, D. Milne and P. Germain, Centre de Recherche Noranda

The practical determination of optimum stope geometry has, until recently, been an art relying primarily on experience at a given operation. Due to the complex and variable nature of rock masses in situ, slopes are often designed either very conservatively, resulting in excess development, or nonconservative resulting in excessive dilution and, in some cases, in loss of ore reserves. The Geomechanics group of the Mining Technology Division, Centre de Recherche Noranda, uses a combination numerical modelling and empirical design techniques to optimize allowable stope geometries. The above methodology allows the optimization of stope geometry for varying rockmass classifications within an operation or between different operations. Such techniques require the development of a thorough geotechnical database at each operation and are best used when calibrated to the specific operation through back analysis. This paper discusses the above optimization techniques in light of specific examples from the Noranda Group. The design methods, limitations and results are discussed.
Keywords: Rock mechanics, Stope design, numerical-modelling, Empirial design, Mine design, Slope stability