Authors: Dunn, MJ

Open access courtesy of:

Cite As:
Dunn, MJ 2019, 'Quantifying uncertainty in mining geomechanics design', in J Wesseloo (ed.), Proceedings of the First International Conference on Mining Geomechanical Risk, Australian Centre for Geomechanics, Perth, pp. 391-402.

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
Uncertainty in mining geomechanics and geotechnical engineering is a broad term that accounts for natural variability, lack of data, and lack of knowledge. Reducing uncertainty is a key component of the mining study process and in managing geomechanical/geotechnical risk. Understanding and reducing uncertainty is also a key activity in the design process to ensure that designs are robust and resilient. A variety of methods are used in geomechanical design including empirical, analytical and numerical modelling. All design methods require inputs, and these are based on data from core logging, mapping, laboratory testing, field observations, and monitoring. This data then must be compiled and interpreted so that meaningful and reliable design inputs with a reliability that is commensurate with the level of design (scoping through to operational) can be derived. This includes the development of the geomechanical or geotechnical model. The uncertainty of the geotechnical model is often described in terms of confidence or reliability. Currently, very little quantitative guidance exists in the literature on assessing the confidence level of geotechnical studies and design, although there have been attempts by various authors (Haile 2004; Haines et al. 2006; Read 2009; Dunn et al. 2011) to qualitatively describe what level of geotechnical data is required. Several authors have outlined methods that could be applied to assess the reliability of geotechnical data (Read 2013; Fillion & Hadjigeorgiou 2013; Dunn 2015). Data from a range of projects are reviewed and summarised and an attempt made to quantify the uncertainty for some data, and illustrate the impact this can have on designs and commonly used design acceptance criteria.

Keywords: uncertainty, risk, reliability

References:
Baecher, GB & Christian, JT 2003, Reliability and Statistics in Geotechnical Engineering, John Wiley & Sons, London.
Bieniawski, ZT 1989, Engineering Rock Mass Classifications, John Wiley & Sons, New York.
Bieniawski, ZT 1992, ‘Principles of engineering design for rock mechanics’, in JR Tillerson & WR Wawersik (eds), Proceedings of the 33rd US Symposium on Rock Mechanics, Taylor & Francis, pp. 1031–1040.
Brown, ET 2007, Block Caving Geomechanics, Second Edition, Julius Kruttschnitt Mineral Research Centre, Indooroopilly, p. 696.
Cepuritis, P & Villaescusa, E 2012, ‘A reliability-based approach to open stope span design in underground mining’, Proceedings of the 6th International Conference and Exhibition on Mass Mining, Canadian Institute of Mining, Metallurgy and Petroleum, Westmount.
Dunn, MJ 2014, ‘Geotechnical models and data confidence in mining geotechnical design’, Proceedings of the Third Australasian Ground Control in Mining Conference, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 105–112.
Gover, SM 2018, ‘Linking safety factor to probability of failure’, Proceedings Mine Waste and Tailings Stewardship Conference 2018 Conference Proceedings, The Australasian Institute of Mining and Metallurgy, Melbourne.
Hadjigeorgiou, J & Harrison, JP 2011, ‘Uncertainty and sources of error in rock engineering’, in Q Qian & X Zhou (eds), Harmonising Rock Engineering and the Environment: Proceedings of the 12th ISRM International Congress on Rock Mechanics, CRC Press, Leiden, pp. 2063–2067.
Haile, A 2004, ‘A reporting framework for geotechnical classification of mining projects’, AusIMM Bulletin, September/October 2004, Melbourne, pp. 30–37.
Haines, A, Swart, A & Kruger, A 2006, ‘Proactively mitigating geotechnical risks in open pit and underground mining’, in Y Potvin (ed.), Proceedings of the Second International Seminar on Strategic versus Tactical Approaches in Mining, Australian Centre for Geomechanics, Perth.
Harr, ME 1996, Reliability-Based Design in Civil Engineering, McGraw-Hill, Dover.
Jefferies, M, Lorig L & Alvarez, C 2008, ‘Influence of rock strength spatial variability on slope stability’, in R Hart, C Detournay & P Cundall (eds), Proceedings First International FLAC/DEM Symposium on Numerical Modelling, Itasca, Minneapolis.
Joint Ore Reserves Committee 2004, JORC Code: Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, Joint Ore Reserves Committee, Carlton South.
Joint Ore Reserves Committee 2012, JORC Code: Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, Joint Ore Reserves Committee, Carlton South.
Lambe, TW 1985, ’Amuay landslides’, Proceedings of 11th International Conference on Soil Mechanics and Foundation Engineering, Golden Jubilee Volume, A.A. Balkema, Rotterdamn, pp. 137–158.
McMahon, BK 1985, ‘Geotechnical design in the face of uncertainty: EH Davis memorial lecture’, Australian Geomechanics Journal, issue 10, pp. 7–19, Australian Geomechanics Society, Barton.
Peck, RB 1969, ‘Advantages and limitations of the observational method in applied soil mechanics’, Géotechnique, vol. 19, no. 2,
pp. 171–187.
Read, J 2009, ‘Data uncertainy’, in J Read & P Stacey (eds), Guidelines for Open Pit Slope Design, CSIRO Publishing, Collingwood, pp. 213–220.
Renani, HR, Martin, CD, Varona, P & Lorig, L 2018, ‘Probabilistic stability analysis of slopes in highly heterogeneous rock masses’, Proceedings of Slope Stability Symposium 2018, BCO Congresos, Barcelona.
Silva, FM, Lambe, TW & Marr, WA 2008, ‘Probability and Risk of Slope Failure’, Journal of Geotechnical and Geoenvironmental Engineering, vol. 134, no. 12.
Stacey, TR 2004, ‘The link between the design process in rock engineering and the code of practice to combat rock fall and rockburst accidents’, The Journal of The South African Institute of Mining and Metallurgy, pp. 29–34.
Stacey, TR 2009, ‘Design—a strategic issue’, The Journal of The Southern African Institute of Mining and Metallurgy, vol. 109,
pp. 157–162.
Steffen, OKH 1997, ‘Planning of open pit mines on risk basis’, The Journal of The South African Institute of Mining and Metallurgy, vol. 2, pp. 47–56.
Tapia, A, Contreras, LF, Jefferies, M, & Steffen, O 2007, ‘Risk evaluation of slope failure at the Chuquicamata mine’, in Y Potvin (ed.), Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 477–495.
Venter, J 2018, ‘Slope design – from A to Z’, Geotechnical Engineering for Open Pit Open Mines Course, Australian Centre for Geomechanics, Perth.
Villaescusa, E 2014, Geotechnical Design for Sublevel Open Stoping, CRC Press, Boca Raton, p. 541.
Vyazmensky, A 2017, Geotechnical or Geomechanical?, Minex Forum,
Wiles, TD 2006, ‘Reliability of numerical modelling predictions’, International Journal of Rock Mechanics and Mining Sciences, vol. 43, pp. 454–472.




© Copyright 2019, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
Please direct any queries or error reports to repository-acg@uwa.edu.au