Zermatten, C & Terbrugge, PJ 2016, 'Difficulties establishing a common understanding to address risk in mining — challenges in meaningful communication of probabilistic expressions', in PM Dight (ed.), APSSIM 2016: Proceedings of the First Asia Pacific Slope Stability in Mining Conference
, Australian Centre for Geomechanics, Perth, pp. 339-351, https://doi.org/10.36487/ACG_rep/1604_19_Zermatten
Risk assessments are routinely undertaken for different aspects during the planning, design, optimisation and operation of open pit mines. However, definition of key terms during the risk assessment process may differ between evaluators, which are not always communicated to the range of stakeholders who rely on the resultant information and recommendations.
This paper differentiates terminology related to risk and the assessment thereof, identifies common shortcomings in risk assessments and proposes effective elements in communicating the findings of risk assessments within the context of open pit mining. The crux of this paper is to address quantification of probabilistic expressions for the purpose of efficient and accessible communication to stakeholders.
Keywords: risk management, quantification, probabalistic expression
Abdel Sabour, SA & Dimitrakopoulos, R 2011, ‘Incorporating geological and market uncertainties and operational flexibility into open pit mine design’, Journal of Mining Science, vol. 47, no. 2, pp. 191–201.
Adams, BA 2015, ‘Slope Stability Acceptance Criteria for Opencast Mine Design’, in Proceedings of the Twelfth Australia New Zealand Conference on Geomechanics, New Zealand Geotechnical Society and the Australian Geomechanics Society, Wellington, p. 8.
Australian Government (Department of Resources, Energy and Tourism) 2008, Risk assessment and management, p. 85.
Aven, T 2009, ‘Risk analysis and management’, Journal Reliability: Theory and Applications, pp. 57–73.
Baecher, GB & Christian, JT 2003, Reliability and Statistics in Geotechnical Engineering, Wiley, Chichester, UK.
Bedi, A 2013, A proposed framework for characterising uncertainty and variability in rock mechanics and rock engineering, Thesis submitted for the degree of Doctor of Philosophy and Diploma of Imperial College, London.
Blees, W 2011, ‘Enterprise risk management – a balancing act’, Risk Australia, Spring, pp. 19–21.
Bristow, M, Fang, L & Hipel, KW 2012, ‘System of Systems Engineering and Risk Management of Extreme Events: Concepts and Case Study’, Risk Analysis, vol. 32, no. 11, pp. 1935–1955.
Brown, T & Booth, A 2008, ‘Risk Management’, in J Read & P Stacey (eds), Guidelines for Open Pit Slope Design, CSIRO Publishing.
Chiwaye, HT & Stacey, TR 2010, ‘A comparison of limit equilibrium and numerical modelling approaches to risk analysis for open pit mining’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 110, pp. 571–580.
Christian, JT 2004, ‘Geotechnical engineering reliability: How well do we know what we are doing?’, Journal of Geotechnical and Geoenvironmental Engineering, October, pp. 985–1001.
Christian, J, Ladd, C & Baecher, G 1994, ‘Reliability applied to slope stability analysis’, Journal of Geotechnical Engineering, vol. 120, no. 12, pp. 2180–2207.
Contreras, L-F 2015, ‘An economic risk evaluation approach for pit slope optimization’, Journal of The Southern African Institute of Mining and Metallurgy, vol. 115, pp. 607–622.
Costard, S 2008, Introduction to Risk Analysis and Risk Assessment, pp. 44, viewed 30 September 2008,
Dimitrakopoulos, R & Grieco, N 2009, ‘Stope design and geological uncertainty: quantification of risk in conventional designs and a probabilistic alternative’, Journal of Mining Science, vol. 45, no. 2, pp. 152–163.
Dunn, M 2014, ‘Geotechnical models and data confidence in mining geotechnical design’, in PC Hagan & S Saydam (eds), Proceedings of the Third Australasian Ground Control in Mining Conference, Melbourne, pp. 127–133.
Elmouttie, M & Poropat, GV 2011, ‘Uncertainty propagation in structural modelling’, in E Eberhardt & D Stead (eds), Proceedings of the International Symposium on Stability of Rock Slopes in Open Pit Mining and Civil Engineering 2011, Vancouver.
Engineers Canada n.d., Risk Management, viewed 09 April 2016,
Engström, A & Stålsmeden, D 2011, Geotechnical Risk Communication: A case study of communication between actors in infrastructure projects, Master of Science Thesis in the Master’s Programme Geo and Water Engineering.
Fenton, GA (ed.) 1997, Probabilistic Methods in Geotechnical Engineering, ASCE Geotechnical Safety and Reliability Committee.
Fink, G, Steiger, R & Köhler, J 2009, Definitions of robustness and related terms, in J Köhler, H Narasimhan & MH Faber (eds), Proceedings of the Joint Workshop of European Cooperation in Science and Technology (COST) Actions TU0601 and E55, European Cooperation in Science and Technology, Ljubljana, Slovenia, pp. 21–25.
Granger Morgan, M 2001, Analyzing and Communicating Uncertainty, An overview talk for the 4th UCAR/NCAR Junior Faculty Forum on Future Scientific Directions, 2006 August 01, Carnegie Mellon University.
Granger Morgan, M & Henrion, M 1990, Uncertainty: A guide to dealing with uncertainty in quantitative risk and policy analysis, Cambridge University Press.
Groeneveld, B & Topal, E 2011, ‘Flexible open pit mine design under uncertainty’, Journal of Mining Science, vol. 47, no. 2, pp. 212–226.
Hadjigeorgiou, J & Harrison, JP 2011, ‘Uncertainty and sources of error in rock engineering’, in Q Qian and X Zhou (eds), Proceedings of the Twelfth ISRM International Congress on Rock Mechanics: Harmonising Rock Engineering and the Environment, Beijing, pp. 2063–2067.
Harman, J, Hormazabal, E & Martinez, C 2007, ‘Fact and Fiction about pit slope depressurisation’, in Y Potvin (ed.), Proceedings of the International Symposium on Stability of Rock Slopes in Open Pit Mining and Civil Engineering 2007, Australian Centre for Geomechanics, Perth, pp. 361–370.
Hoffman, FO & Kaplan, S 1999, ‘Beyond the domain of direct observation: How to specify a probability distribution that represents the “State of Knowledge” about uncertain inputs’, Risk Analysis, vol. 19, no. 1, pp. 131–134.
Hudson, JA & Feng, X-T 2011, Rock engineering risk, CRC Press: Taylor and Francis Group.
Hussein Malkawi, AI, Hassen, WF & Abdulla, FA 2000, ‘Uncertainty and reliability analysis applied to slope stability’, Structural Safety, vol. 22, pp. 161–187.
Kaplan, S 1997, ‘The words of risk analysis’, Risk Analysis, vol. 17, no. 4, pp. 407–417.
Kaplan, S & Garrick, BJ 1981a, ‘On the quantitative definition of risk’, Risk Analysis, vol. 1, no. 1, pp. 11–27.
Kaplan, S & Garrick, BJ 1981b, ‘Some Misconceptions About Misconceptions: A Response to Abramson’, Risk Analysis, vol. 1, no. 4, pp. 231–233.
Macciotta, R, Derek Martin, C & Morgenstern, NR 2010, ‘Risk management of large rock slopes – state of practice’, in Proceedings of the 63rd Canadian Geotechnical Conference, Canadian Geotechnical Society, Calgary, Alberta, pp. 891–898.
Morgenstern, NR 1995, ‘Managing Risk in Geotechnical Engineering’, The Third Casagrande Lecture, in Proceedings of the Tenth PanAmerican Conference on Soil Mechanics and Foundation Engineering, Guadalajara, Mexico, vol. 4, pp. 102–126.
Mosteller, F & Youtz, C 1990, ‘Quantifying probability expressions’, Statistical science, vol. 5, no. 1, pp. 2–34.
Palmström, A 1995, RMi - a rock mass characterization system for rock engineering purposes, PhD thesis, Oslo University, Norway, p. 400.
Pappenberger, F & Beven, KJ 2006, ‘Ignorance is bliss: Or seven reasons not to use uncertainty analysis’, Water resources research, vol. 42, p. 78.
Pilch, M, Trucano, TG & Helton, JC 2006, Ideas Underlying Quantification of Margins and Uncertainties (QMU): A White Paper, Sandia National Laboratories Albuquerque, New Mexico, pp. 1–35.
Read, J 2008, ‘Data uncertainty’, in J Read & P Stacey (eds), Guidelines for Open Pit Slope Design, CSIRO Publishing.
Read, J 2013, ‘Data gathering, interpretation, reliability and geotechnical models’, in PM Dight (ed.), Proceedings of Slope Stability 2013, Australian Centre for Geomechanics, Perth, Western Australia, pp. 81–89.
Ros, IT & Van As, A 2012, ‘Major Hazards Associated with Block Caving’, in Proceedings of MassMin 2012: Sixth International Conference & Exhibition on Mass Mining, Canadian Institute of Mining, Metallurgy and Petroleum, Ontario, Canada, p. 9.
Ross, SM 2007, Introduction to probability models, Elsevier Incorporated.
Royal Society of Chemistry 2001, ‘Robust statistics: a method of coping with outliers’, Analytical Methods Committee (AMC) Technical Brief, no. 6, p. 1.
Scarborough, J 2011 ‘Communicating and Managing Risk in Geotechnical Engineering Practice’, in CH Juang, KK Phoon, AJ Puppala, RA Green & GA Fenton (eds), Proceedings of GeoRisk 2011: Geotechnical Risk Assessment and Management, American Society of Civil Engineers, Atlanta, pp. 560–567.
Sniedovich, M 2012, ‘Fooled by local robustness’, Risk Analysis, vol. 32, no. 10, pp. 1630–1637.
Society for Risk Analysis (SRA) Committee on the Foundation of Risk Analysis 2015, SRA Glossary, Rationale and Process, viewed 10 April 2016,
Standards Australia 2004, AS/NZS 4360:2004 Risk Management, Standards Australia, Sydney.
Steffen, OKH 1997, ‘Planning of open pit mines on a risk basis’, Journal of The Southern African Institute of Mining and Metallurgy, March/April 1997, pp. 48–56.
Steffen, OKH, Terbrugge, PJ, Wesseloo, J & Venter, J 2006, ‘A Risk Consequence Approach To Open Pit Slope Design’, in Proceedings of the Southern African Institute of Mining and Metallurgy International Symposium on Stability of Rock Slopes in Open Pit Mining and Civil Engineering, Cape Town, South Africa, pp. 81–96.
Steffen, OKH, Contreras, L-F, Terbrugge, PJ & Venter, J 2008, ‘A risk evaluation approach for pit slope design’, Proceedings of the 42nd US Rock Mechanics Symposium and 2nd U.S.-Canada Rock Mechanics Symposium, p. 18.
Taleb, NN 2007, The Black Swan: the impact of the highly improbable, New York, Random House, p. 366.
Terbrugge, PJ, Steffen, OKH & Contreras, L-F 2009, ‘Value and Risk in Slope Design’, in JR Read (ed.), Proceedings of International Symposium on Rock Slope Stability in Open Pit and Civil Engineering, Chile, p. 7.
Venter, J 2015, ‘Probability of failure in open pit slope design’, in Proceedings of Slope Stability 2015, The Southern African Institute of Mining and Metallurgy in collaboration with the South African National Institute of Rock Engineering, pp. 431–422.
Vicks, SJ 2002, Degrees of Belief, Virginia, ASCE Press.
Wallsten, TS, Budescu, DV, Rapoport, A, Zwick, R & Forsyth, BH 1986, ‘Measuring the vague meanings of probability terms’, Journal of Experimental Psychology, vol. 115, pp. 348–365.
Wilson, L & McCutcheon, DJ 2003, Industrial Safety and Risk Management, Edmonton, AB, University of Alberta Press.
Zermatten, C 2016, ‘Towards reliable geoscientific data and improved confidence in reporting through existing guidelines and standards: a case for inclusion in SAMCODES reporting’, in Proceedings of the SAMREC/SAMVAL Companion Volume Conference, The Southern African Institute of Mining and Metallurgy, Johannesburg, South Africa, p. 13, in press.