Authors: Tierney, SR; Morkel, IG
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Abstract:
The hazard posed from large seismic events is often high enough to warrant the exclusion or evacuation of personnel from underground workings. A period of exclusion is often determined following blasts or large events due to the increased risk. The period of exclusion until re-entry occurs is a decision for site geotechnical engineers and mine management that must balance the potential risk to personnel with lost production time and associated costs. There is currently no widely accepted method for determining reentry times and mine sites typically develop their own rules for exclusions after blasts and large events. A systematic and evidence based approach to the development of re-entry protocols could potentially reduce the risk to personnel from an early re-entry or reduce the lost production from an unnecessary exclusion. Four methods of re-entry assessment have been considered in this paper. The seismic responses at three mines have been modelled and used to optimise each assessment method and gauge the relative success through back-analysis. These same techniques are available for other mines to review their own data and potentially improve their current re-entry protocols. The results of this research indicate that a realtime reentry assessment method can offer improved outcomes compared to blanket re-entry rules by reducing the average exclusion time while still capturing the same number of large events. The incorporation of event size in the assessment can result in better results than the event count. Vallejos and McKinnon (2009) developed a probabilistic framework for re-entry assessment but this method was found to be less efficient than the blanket rule in the majority of cases in this study. The method would also result in more administration and uncertainty for mine planning and scheduling. Several potential improvements to the analysis techniques, and avenues for further research, have been discussed.

Keywords: seismic re-entry, seismic risk, mine seismology

Citation:
Tierney, SR & Morkel, IG 2017, 'The optimisation and comparison of re-entry assessment methodologies for use in seismically active mines', in J Wesseloo (ed.), Proceedings of the Eighth International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 183-196.

References:
Alcott, JM, Kaiser, PK & Simser, BP 1998, ‘Use of microseismic source parameters for rockburst hazard assessment’, Pure and Applied Geophysics, vol. 153, pp. 41–65.
Anderson, TW & Darling, DA 1954, ‘A test of goodness of fit’, Journal of the American Statistical Association, vol. 49, no. 268,
pp. 765–769.
Beck, DA & Brady, BHG 2002, ‘Evaluation and application of controlling parameters for seismic events in hard-rock mines’, International Journal of Rock Mechanics and Mining Sciences, vol. 39, pp. 633–642.
Beck, DA, Brady, BHG & Grant, D 1997, ‘Induced stress and microseismicity in the 3000 orebody, Mount Isa’, Geotechnical and Geological Engineering, vol. 15, pp. 221–233.
Bottiglieri, M, Lippiello, E, Godano, C & de Arcangelis, L 2009, ‘Identification and spatiotemporal organization of aftershocks’, Journal of Geophysical Research: Solid Earth, vol. 114, no. B3, pp. 1–12.
Cook, NGW 1976, ‘Seismicity associated with mining’, Engineering Geology, vol. 10, pp. 99–122.
Hadjigeorgiou, J & Potvin, Y 2011, ‘A critical assessment of dynamic rock reinforcement and support testing facilities’, Rock Mechanics and Rock Engineering, vol. 44, no. 5, pp. 565–578.
Harris, PC & Wesseloo, J 2015, mXrap, version 5, Australian Centre for Geomechanics, Perth, www.mXrap.com
Kahneman, D 2003, ‘A perspetive on judgement and choice - mapping bounded rationality’, American Psychologist, vol. 58, no. 9, pp. 697–720.
Mendecki, A 2008, ‘Forecasting seismic hazard in mines’, in Y Potvin, J Carter, A Dyskin & R Jeffery (eds), Proceedings of The First Southern Hemisphere International Rock Mechanics Symposium, vol. 1, 16–19 September 2008, Perth, Australian Centre for Geomechanics, Perth, pp. 55–71.
Morkel, IG & Wesseloo, J 2017, ‘A method to determine systematic shifts in micro-seismic databases’, in J Wesseloo (ed.), Proceedings of The Eighth International Conference on Deep and High Stress Mining, 28–30 March 2017, Perth, Australian Centre for Geomechanics, Perth, in Print.
Nyffenegger, P & Frohlich, C 2000, ‘Aftershock occurrence rate decay properties for intermediate and deep earthquake sequences’, Geophysical Research Letters, vol. 27, no. 8, pp. 1215–1218.
Ogata, Y 1983, ‘Estimation of the parameters in the Modified Omori Formula for aftershock frequencies by the Maximum Likelihood Procedure’, Journal of Physics of the Earth, vol. 31, no. 2, pp. 115–124.
Omori, F 1894, ‘On the after-shocks of earthquakes’, The Journal of the College of Science, vol. 7, Imperial University of Tokyo, Tokyo, pp. 111-200.
Orlecka-Sikora, B, Lasocki, S, Lizurek, G & Rudziński, Ł 2012, ‘Response of seismic activity in mines to the stress changes due to mining induced strong seismic events’, International Journal of Rock Mechanics and Mining Sciences, vol. 53, pp. 151–158.
Penney, AR & Hills, PB 2013, ‘Development of seismic heading re-entry and exclusion zones at the Tasmania mine’, in A Malovichko & D Malovichko (eds), Proceedings of The 8th International Symposium on Rockbursts and Seismicity in Mines (RaSiM8), Saint Petersburg and Moscow, Geophysical Survey of Russian Academy of Sciences, Obninsk, Mining Institute of Ural Branch of Russian Academy of Sciences, Perm, pp. 447-459.
Potvin, Y 2009, ‘Strategies and tactics to control seismic risks in mines’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 109, no. 3.
Potvin, Y & Hudyma, MR 2001, ‘Seismic monitoring in highly mechanized hardrock mines in Canada and Australia’, in G van Aswegen, R Durrheim & D Ortlepp (eds), Proceedings of The Fifth International Symposium on Rockburst and Seismicity in Mines 2001, Johannesburg, Southern African Institute of Mining and Metallurgy, Johannesburg, pp. 267–280.
Utsu, T 1961, ‘A statistical study of the occurrence of aftershocks’, Geophysical Magazine, vol. 30, no. 4, pp. 521–605.
Utsu, T, Ogata, Y & Matsu'ura, RS 1995, ‘A centenary of the omoro formula for a decay law of aftershock activity’, Journal of Physics of the Earth, vol. 43, pp. 1–33.
Vallejos, JA & McKinnon, SD 2010, ‘Temporal evolution of afterschock sequences for re-entry protocol development in seismically active mines’, in M van Sint Jan & Y Potvin (eds), Proceedings of The 5th International Seminar on Deep and High Stress Mining, 6–8 October 2010, Santiago, Australian Centre for Geomechanics, Perth, pp. 199–214.
Vallejos, JA & McKinnon, SM 2009, ‘Re-entry protocols for seismically active mines using statistical analysis of aftershock sequences’, in M Diederichs & G Grasselli (eds), The 3rd CANUS Rock Mechanics Symposium, May 2009, Toronto, pp. 1–12.
Woodward, K & Wesseloo, J 2015, ‘Observed spatial and temporal behaviour of seismic rock mass response to blasting’, The Journal of the Southern African Institute of Mining and Metallurgy, vol. 115, no. 11, pp. 1044–1056.
Woodward, K, Wesseloo, J & Potvin, Y 2017, ‘The spatial and temporal assesment of clustered and time-dependent seismic responses to mining’, in J Wesseloo (ed.), Proceedings of The Eighth International Conference on Deep and High Stress Mining, 28–30 March 2017, Perth, Australian Centre for Geomechanics, Perth, in print.




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