Authors: Folgoso Lozano, E; Nöger, M; Ladinig, T; Wagner, H

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2205_94

Cite As:
Folgoso Lozano, E, Nöger, M, Ladinig, T & Wagner, H 2022, 'Development of an unsophisticated numerical simulation model for caving systems', in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 1351-1366, https://doi.org/10.36487/ACG_repo/2205_94

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
The main objective of this publication is the description of an unsophisticated methodology to predict caving and cave propagation for mining purposes based on numerical simulations. The aim of the methodology is to create a user-friendly tool which requires little effort to set up and analyse and which facilitates understanding of cave propagation for practical applications. The methodology is defined as an algorithm which is performed in FLAC3D, version 7.0 (Itasca 2019). The constitutive modelling is based on model elastic behaviour, due to its simplicity and low running times. The algorithm utilises a series of routines that describe and quantify the failure process of rock during caving. The emphasis of the methodology is on simplicity, which is reached by implementing reasonable assumptions regarding the caving situation and the rock mass behaviour. The caving propagation is driven by plastic behaviour; however, to simplify the model the caving algorithm is based on an elastic behaviour and specific functions mimicking the plastic behaviour, namely the degradation processes occurring in the rock mass during caving are accounted for by reducing the mechanical properties of the rock mass and the stress state in degraded zones in a controlled and systematic manner. Sensitivity tests are performed to analyse the weight of the mechanical parameters involved in the caving processes, as well as to optimise the reduction rate of the mechanical properties of the rock mass. The calibration of the caving algorithm is the current stage of the development. The calibration is carried out by analysing the results obtained in the numerical models and the outcome of the semi-empirical methods available in the literature. The unsophisticated caving predicting tool is being developed for its application on the novel raise caving mining method (Ladinig et al. 2022). The caving tool will supply understanding regarding the caving initiation and propagation for the novel raise caving method.

Keywords: caving, numerical simulation, cave propagation, prediction, algorithm

References:
Barton, N 1988, Rock Mass Classification and Tunnel Reinforcement Selection Using the Q-System, ASTM International, West Conshohocken, pp. 59–88.
Bewick, R & Kaiser, PK 2009, ‘Numerical assessment of factor B in Mathews’ method for open stope design’, in M Diederichs
& G Grasselli (eds), RockEng09: Proceedings of the Third Canada-US Rock Mechanics Symposium and the 20th Canadian Rock Mechanics Symposium, pp. 89–90.
Bieniawski, ZT 1976, ‘Rock mass classification in rock engineering’, in ZT Bieniawski (ed), Proceedings of the Symposium on Exploration for Rock Engineering, A.A. Balkema, Rotterdam, pp. 97–106.
Brown, ET 2007, Block Caving Geomechanics, 2nd edn, Julius Kruttschnitt Mineral Research Centre, The University of Queensland, Brisbane.
Brown, ET & Chitombo, GP 2007, Underground Mass Mining by Caving: The Way of The Future, Sustainable Minerals Institute, and Julius Kruttschnitt Mineral Research Centre, Brisbane
Diederichs, MS & Kaiser, PK 1999, ‘Tensile strength and abutment relaxation as failure control mechanisms in underground excavations’, International Journal of Rock Mechanics and Mining Sciences, vol. 36, no. 1, pp. 69–96,
/10.1016/S0148-9062(98)00179-X.
Duplancic, P & Brady, BH 1999, ‘Characterisation of caving mechanisms by analysis of seismicity and rock stress’, Proceedings of the 9th International Congress on Rock Mechanics, A.A. Balkema, Rotterdam, pp. 1049–1053.
Hebert, Y & Sharrock, G 2018, ‘Three-dimensional simulation of cave initiation, propagation and surface subsidence using a coupled finite difference–cellular automata solution’, in Y Potvin & J Jakubec (eds), Caving 2018: Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 151–166.
Hoek, E & Brown, ET 1980, ‘Empirical strength criterion for rock masses’, Journal of the Geotechnical Engineering Division, vol. 106, no. 9, pp. 1013–1035,
Hoek, E & Brown, ET 2019, ‘The Hoek–Brown failure criterion and GSI – 2018 edition’, Journal of Rock Mechanics and Geotechnical Engineering, vol. 11, no. 3, pp. 445–463,
Hoek, E & Diederichs, MS 2006, ‘Empirical estimation of rock mass modulus’, International Journal of Rock Mechanics and Mining Sciences, vol. 43, no. 2, pp. 203–215,
Itasca Consulting Group, Inc. 2019, FLAC3D - Fast Lagrangian Analysis of Continua in Three-Dimensions, version 7.0, computer software, Itasca Consulting Group, Inc., Minneapolis, http://www.itascacg.com/software/FLAC3D
Ladinig, T, Wagner, H, Bergström, J, Koivisto, M & Wimmer, M 2021, ‘Raise caving – a new cave mining method for mining at great depths’, Proceedings of the 5th International Future Mining Conference, Australasian Institute of Mining and Metallurgy, Melbourne, pp. 368–384.
Ladinig, T, Wimmer, M & Wagner, H 2022, ‘Raise caving: a novel mining method for (deep) mass mining’, in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 651–666.
Laubscher, DH 1994, ‘Cave mining – the state of the art’, Journal of the South African Institute of Mining and Metallurgy, vol. 94, no. 10, pp. 279–293.
Laubscher, DH 2000, Block Caving Manual, International Caving Study, and JKMRC and Itasca Consulting Group, Inc, Brisbane.
Mathews, KE, Hoek, E, Wyllie, DC & Stewart, SBV 1981, Prediction of Stable Excavation Spans for Mining at Depths Below 1,000 Metres in Hard Rock, Golder Associates report to CANMET, Department of Energy and Resources.
Mawdesley, C 2002, Predicting Rock Mass Caveability in Block Caving Mines, PhD thesis, University of Queensland, Brisbane.
Mitri, HS, Hughes, R & Zhang, Y 2011, ‘New rock stress factor for the stability graph method’, International Journal of Rock Mechanics and Mining Sciences, vol. 48, no. 1, pp. 141–145, .
Nickson, SD 1992, Cable Support Guidelines for Underground Hard Rock Mine Operations, MSc thesis, The University of British Columbia, Vancouver.
Potvin, Y 1988, Empirical Open Stope Design in Canada, PhD thesis, The University of British Columbia, Vancouver.
Sainsbury, BA 2012, A Model for Cave Propagation and Subsidence Assessment in Jointed Rock Masses, PhD thesis, University of New South Wales, Kingston.
Sainsbury, B, Sainsbury, D & Vakili, A 2015, ‘Discrete analysis of open stope stability’, in Y Potvin (ed.), Design Methods 2015: Proceedings of the International Seminar on Design Methods in Underground Mining, Australian Centre for Geomechanics, Perth, pp. 79–94,
Stewart, P & Trueman, R 2003a, ‘Applying the Extended Mathews stability graph to stress relaxation, site specific effects and narrow vein stoping’, Proceedings of the 1st Australasian Ground Control in Mining Conference - Ground Control in Mining: Technology and Practice, UNSW Publishing and Printing Services, Sydney, pp. 55–61.
Stewart, P & Trueman, R 2003b, ‘Quantifying the effect of stress relaxation on excavation stability’, Mining Technology, vol. 113, no. 2, pp. 107–117, .
Vallejos, JA & Díaz, L 2020, ‘A new criterion for numerical modelling of hangingwall overbreak in open stopes’, Rock Mechanics and Rock Engineering, vol. 53, no. 10, pp. 4559–4581,




© Copyright 2022, 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