Simmons, JV 2020, 'Geomechanics of Australian open cut coal mining', in PM Dight (ed.), Slope Stability 2020: Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 39-64, https://doi.org/10.36487/ACG_repo/2025_0.03
Australian black coal and brown coal mining is an important contributor to the Australian economy. The intent of this paper is to provide concise reference information to geotechnical practitioners. Geology of coals, coal measures rocks, overburdens, and groundwater are described. Mining operations for the black coal and brown coal industries are very different. Both are outlined to provide a context for geotechnical characterisation that covers rank, coal materials, virgin and pre-existing stress states, and data gathering. Geotechnical models and parameters are described separately for the black coal and brown coal sectors. Information is provided regarding material and mass strength, deformability, degradation and weathering, hydraulic conductivity, gas desorption and outburst, and waste dumping. An overview of analytical tools is provided for defect mapping, slope stability, and deformation and groundwater pressure modelling. Discussion of geotechnical aspects of final post-mining landforms is also provided.
Keywords: open cut coal mining, shear strength, extension, deformability, hydraulic conductivity, subsidence
Australian Groundwater and Environmental Consultants Pty Ltd 2017, Report on Project China Stone Additional Information on Groundwater: For MacMines Austasia Pty Ltd, viewed 3 March 2020,
Beale, G & Read, J 2013, Guidelines for Evaluating Water in Pit Slope Stability, CSIRO Publishing, Collingwood.
Beamish, B, Edwards, D & Theiler, J 2015, ‘Case study of an opencut coal mine self-heating event benchmarked against a new laboratory test method’, in JW Beeston (ed.), Proceedings of the Bowen Basin Symposium, Coal Geology Group and The Bowen Basin Geologists Group, Brisbane, pp. 13–21.
Bioregional Assessments 2018, Hydrogeology and groundwater quality. Australian Government, viewed 20 January 2020,
Currell, MJ, Werner, AD, McGrath, C, Webb, JA & Berkman, M 2017, ‘Problems with the application of hydrogeological science to regulation of Australian mining projects: Carmichael Mine and Doongmabulla Springs’, Journal of Hydrology, vol. 548,
Department of Jobs Precincts and Regions 2019, Latrobe Valley Regional Rehabilitation Strategy Regional Geotechnical Study Synopsis Report, viewed 4 March 2020,
Duncan, JM & Wright, SG 2005, Soil Strength and Slope Stability, John Wiley & Sons Inc., Hoboken.
Fityus, SG, Jeffery, M, Aglias, KJ, Johnston, JA & Simmons, JV 2015, ‘Weathering and degradation of shales and mudrocks’, Proceedings of the 13th International Congress on Rock Mechanics, Canadian Institute of Mining, Metallurgy & Petroleum, Toronto.
Geoscience Australia 2013, Australia’s Mineral Resource Assessment 2013, Australian Government, viewed 23 January 2020,
GNS Science 2020, Coal Formation, viewed 5 February 2020,
Green, DR 2015, CoalLog Geology and Geotechnical Training Manual, ACARP Project C22017, viewed 3 March 2020,
Hawley, M & Cunning, J 2017, Guidelines for Mine Waste Dump and Stockpile Design, CSIRO Publishing, Collingwood.
Hazelwood Mine Fire Inquiry 2016, Hazelwood Mine Fire Inquiry 2015/2016 Volume IV Mine Rehabilitation, Department of Economic Development, Jobs Transport and Resources, viewed 26 February 2020,
Henderson, S & Merritt, J 2015, ‘A framework for void stability assessment within mine closure planning’, in JW Beeston (ed.), Proceedings of the Bowen Basin Symposium, Coal Geology Group and The Bowen Basin Geologists Group, Brisbane,
Hillis, RR, Enever, JR & Reynolds, SD 1999, ‘In situ stress field of eastern Australia’, Australian Journal of Earth Sciences, vol. 46,
Hoek, E & Brown, ET 2018, ‘The Hoek-Brown failure criterion and GSI – 2018 edition’, Journal of Rock Mechanics and Geotechnical Engineering, vol. 11, issue 3, pp. 445–463,
Holdgate, GR 2003, ‘Coal, world class energy reserves without limits’, in WD Birch (ed.), Geology of Victoria, Special Publication 23, Geological Society of Australia, pp. 489–518.
Holdgate, GR 2005, ‘Geological processes that control lateral and vertical variability in coal seam moisture contents—Latrobe Valley (Gippsland Basin) Australia’, International Journal of Coal Geology, vol. 63, pp. 130–155.
Holtz, RD & Kovacs, WD 1981, An Introduction to Geotechnical Engineering, Prentice-Hall, Upper Saddle River.
Kavvadas, M, Papadopoulos, B & Kaltezoitis, N 1994, ‘Geotechnical properties of the Ptolemais lignite’, Geotechnical and Geological Engineering, vol. 12, no. 87,
Kavvadas, M, Agiotantis, Z, Schilizzi, P & Steiakakis, C 2013, ‘Stability and movements of open-pit lignite mines in Northern Greece’, Proceedings of the 18th International Conference on Soil Mechanics and Foundation Engineering, International Society for Soil Mechanics and Geotechnical Engineering, London, pp. 2193–2196.
Koosmen, K, Simmons, J & Fityus, S 2015, ‘Considerations for the design of spoil piles containing co-disposed washery wastes’, in JW Beeston (ed.), Proceedings of the Bowen Basin Symposium, Coal Geology Group and The Bowen Basin Geologists Group, Brisbane, pp. 371–382.
Mackie, CD 2009, Hydrogeological Characterisation of Coal Measures and Overview of Impacts of Coal Mining on Groundwater Systems in the Upper Hunter Valley of NSW, PhD Thesis, University of Technology Sydney, Sydney.
Mackie Environmental Research 2009, Groundwater management studies ravensworth operations project, Report to Ravensworth Operations Pty Limited, viewed 3 March 2020,
Martin, D & Stacey, P 2018, Guidelines for Open Pit Slope Design in Weak Rocks, CSIRO Publishing, Collingwood.
McQuillan, A, Canbulat, I, Payne, D & Oh, J 2018, ‘New risk assessment methodology for coal mine excavated slopes’, International Journal of Mining Science and Technology, vol. 28, pp. 583–592,
Medhurst, TP & Brown, ET 1998, ‘A study of the mechanical behaviour of coal for pillar design’, International Journal of Rock Mechanics and Mining Science, vol. 35, no. 8, pp. 1087–1105.
Metcalf, JR 1966, ‘Angle of repose and internal friction’, International Journal of Rock Mechanics and Mining Sciences, vol. 3,
Moein, F, Xue, J, Dent, B & Mackay, R 2016, ‘Review of the historical data characterizing Latrobe Valley brown coal consolidation behaviour’, in M Eggers, JS Griffiths, S Parry & MG Culshaw (eds), Developments in Engineering Geology. Engineering Geology Special Publication 27, The Geological Society, London, pp. 217–226,
Rajabi, M, Tingay, M, Heidbach, O, Hillis, R & Reynolds, S 2017, ‘The present-day stress field of Australia’, Earth-Science Reviews, vol. 168, pp. 165–189,
Raymond, OL 2012, Surface Geology of Australia 1:1M Data Set, A3 map image, Geoscience Australia, viewed 5 February 2020,
Seddon, K 2013, Review of Failure of Morwell River Diversion Yallourn, ATC Williams Report Ref.112179.01R01 to Department of Primary Industries, Victoria,
Selley, RC 1996, Ancient Sedimentary Environments, 4th edn, Chapman & Hall, London.
Sherwood Geotechnical and Research Services 2011, ESFC-Based Trigger Levels for Monitoring Pit Wall Stability, Report Number 7260-1-2, Australian Coal Association Research Program.
Simmons, JV & McManus, DA 2004, ‘Shear strength framework for design of dumped spoil slopes for open pit coal mines’, in RJ Jardine, DM Potts & KG Higgins (eds), Advances in Geotechnical Engineering The Skempton Conference, London,
Simmons, JV 2013, ‘Geotechnical support for open pit coal mining’, Australian Geomechanics, vol. 48, no. 1, pp. 85–100.
Simmons, JV & Fityus, SG 2016, The Stability of Very High Spoil Piles, Report for ACARP Project C20019, Australian Coal Association Research Program.
Simmons, JV & Yarkosky, RR 2017, ‘Dragline Spoils’, in PM Hawley & J Cunning (eds), Guidelines for Mine Waste Dump and Stockpile Design, CSIRO Publishing, Clayton, pp. 233–258.
Simmons, J, Ebeling, P & Stacey, P 2018, ‘Weak Sedimentary Coal, Chalk and Limestone’, D Martin & P Stacey (eds), Guidelines for Open Pit Slope Design in Weak Rocks, CSIRO Publishing, Clayton, pp. 203–232.
Simmons, JV 2019, ‘Implications of groundwater pressure models for slope stability assessment’, in HE Acosta-Martinez & BM Lehane (eds), Proceedings of the 13th Australia New Zealand Conference on Geomechanics, Australian Geomechanics Society, St Ives, pp. 505–510.
Sirevaag, H, Ksienzyk, A K, Jacobs, J, Dunkl, I & Laufer, A 2018, ‘Tectono-thermal evolution and morphodynamics of the Central Dronning Maud Land Mountains, East Antarctica, based on new thermochronological data’, Geosciences, vol. 8, issue 11,
Smerdon, BD & Ransley, TR 2012, Water Resource Assessment for the Surat Region, Report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment,
Srithar, S & Ervin, M 2007, ‘River diversion over a backfilled open cut brown coal mine’, in J Ameratunga, B Taylor & M Patten (eds), Proceedings of the 10th Australia New Zealand Conference on Geomechanics, Australian Geomechanics Society and the New Zealand Geotechnical Society Inc., St Ives, pp. 306–311.
Standards Australia 2017, Geotechnical site investigations AS1726:2017, Standards Australia.
Standards Australia 1987, Classification and Coding Systems for Australian Coals A2096:1987, Standards Australia.
Stefanizzi, S, Barla, G & Kaiser, PK 2007, ‘Numerical modelling of strain driven fractures around tunnels in layered rock masses’, in L Ribeira de Souza, C Olalla & N Grossman (eds), Proceedings 11th International Congress on Rock Mechanics, Taylor & Francis, Lisbon, pp. 971–974.
Sullivan, T 2008, Mining Warden Report Yallourn Mine Batter Failure Inquiry, Victorian Government Printer,
Trollope, DH, Rosengren, KJ & Brown, ET 1965, ‘The mechanics of brown coal’, Geotechnique, vol. 15, no. 4, pp. 363–386.
Waghorne, EP 2009, ‘Brown coal mining in the Latrobe Valley’, Monograph 12 Australasian Coal Mine Practice, 3rd edn, The Australasian Institute of Mining and Metallurgy, Carlton, pp 470–485.
Willgoose, G 2018, Principles of Soilscape and Landscape Evolution, Cambridge University Press, Cambridge, 324 p.
Wylie, DC & Mah, CW 2004, Rock Slope Engineering, Civil and Mining, 4th edn, Spon Press, London 431 p.