Statistical assessment of intact rock properties for two underground mining projects at Raglan Mine, Quebec, Canada

CIM Journal Preprints, Vol. 11, No. 1, 2020

M. Grenon, C. Boudreau, and G. Bruneau
Université Laval, Quebec City, Quebec, Canada

R. Caumartin
Raglan Mine – A Glencore Company, Quebec, Canada

The design of underground mining excavations relies on geotechnical characterization of intact rock through laboratory testing. As mining project development progresses though prefeasibility to production stages, the reliability of estimates of rock mechanics properties needs to increase. However, it is challenging to determine the number of tests needed to adequately estimate intact rock properties at different development stages. This paper looks at the early stages of an underground mining project in the Canadian arctic where two field and laboratory testing campaigns were conducted to evaluate intact rock tensile and uniaxial compressive strength. Results were statistically compared to target confidence levels associated with different stages of a mining project. The study provides insights for planning future field and laboratory testing campaigns. The methodology also provides a quantitative means to assess whether additional laboratory testing is needed to improve tensile and uniaxial compressive strength estimates.

Keywords: Brazilian tensile strength (BTS), Data confidence, Geotechnical level (GL), Intact rock properties, Laboratory tests, Statistical analysis, Target level of data confidence (TLDC), Underground mining project, Uniaxial compressive strength (UCS)