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PHYSICS OF ROCKS AND PROCESSES
ArticleName Knowledge base system on preconditioning practices in rockburst prone ground conditions
DOI 10.17580/em.2020.01.03
ArticleAuthor Sengani F.
ArticleAuthorData

Department of Geology and Mining, University of Limpopo, Polokwane, South Africa:

Sengani F., Acting Head of Department Geology and Mining, and Lecturer, PhD (Rock Mechanics) Сandidate, Professional Rock Mechanical Scientist, fhatuwani.sengani@ul.ac.za

Abstract

Preconditioning techniques have been applied in rockburst prone mines around the world to redistribute the stress peak further into the solid region ahead of the mining face by eradicating the strain energy in the asperities of the mining-induced fractures. This paper reviewed the application of preconditioning practice, specifically in South African hard rock mines and outline gap knowledge revolving around this study. The study has shown that there are two types of preconditioning techniques (face perpendicular and parallel). Only face perpendicular preconditioning practice has been documented to have been successfully implemented in both conventional and fully mechanized gold mines. In this paper, it is maintained that although this technique has been reported to have been successfully implemented in many cases, there are still unanswered questions concerning this technique, therefore it is argued that this practice cannot be made an international practice before this gap knowledge are well addressed.

keywords Face perpendicular preconditioning, Face parallel preconditioning practice, Rockburst, Rock fracturing, Radial fractures, Rockburst, Seismic events
References

1. Annual report on fatalities in mining industries of South Africa. Department of Mineral Resource (DMR), South Africa, 2017. pp. 7–18.
2. Kaiser P. K., Tannant D. D., McCreath D. R. Canadian rockburst support handbook: Geomechanics research Centre. Sudbury, Ontario : Laurentian University, 1996.
3. Cai M., Kaiser P. K. Rockburst Support Reference Book. Vol. 1: Rockburst phenomena and support characteristics. MIRARCO, Laurentian University, Sudbury, Ontario, 2018.
4. Ortlepp W. D. (Ed). Rock Fracture and Rockbursts – An Illustrative Study. Johannesburg : The South African Institute of Mining and Metallurgy, 1997. 98 p.
5. Ortlepp W. D., Stacey T. R. Rockburst mechanisms in tunnels and shafts. Tunnelling and Underground Space Technology. 1994. Vol. 9(1). pp. 59–65.
6. Sengani F., Zvarivadza T. Review of pre-conditioning practice in mechanized deep to ultra-deep level gold mining. 26th International Symposium on Mine Planning and Equipment Selection. Lulea, Sweden, 29-31 August 2017.
7. Brummer R. K. Literature review – Destressing. COMRO Internal Report, IR 300. Johannesburg, May 1985.
8. Ryder J. A., Brummer R. K., Spottiswoode S. M. Strategies for controlling the rockburst hazard. Mine Safety and Health Congress. Johannesburg, 19–20 November 1987.
9. Toper A. Z. The effect of blasting on the rockmass for designing the most effective preconditioning blasts in deep level gold mines: PhD thesis. University of the Witwatersrand Johannesburg, School of Mining Engineering, South Africa, 2003
10. Sengani F., Zvarivadza T., Adoko A. C. The Comparison of two adopted face perpendicular preconditioning techniques. Mining Technology. 2018. Vol. 128(1). pp. 21–38. DOI: 10.1080/25726668.2018.1517204.
11. Sengani F., Amponsah-Dacosta F. The application of the face-perpendicular preconditioning technique for de-stressing seismically active geological structures. Mining Technology. 2018. Vol. 127(4) pp. 241–255, DOI: 10.1080/2572668.2018.1497871
12. Hill F. G., Plewman R. P. Destressing: A means of ameliorating rockburst conditions. Part 2 – Implementing destressing with a discussion on the results so far obtained. Journal of SAIMM. October 1957. pp. 120–127.
13. Cook N. G. W., Hoek E., Pretorius J. P. G., Ortlepp W. D., Salamon M. D. G., Rock mechanics applied to the study of rockbursts. Journal of the South African Institute of Mining and Metallurgy. May 1966. pp. 435–528.
14. Hill F. G. An investigation into the problem of rockbursts: an operational research project. Part I. The approach to the problem and analyses of the rockbursts that have occurred on the E.R.P.M. during the years 1948–1953. Journal of the Chemical, Metallurgical and Mining Society of South Africa. 1954. Vol. 55. pp. 63–83.
15. Cook N. G. W. Origin of rockbursts. Proc. of the Symposium on Rockbursts: prediction and control. IMM and IME, London, October 1983. pp. 1–9.
16. Toper A. Z., Kabongo K. K., Stewart R. D., Daehnke A. The mechanism, optimisation and effects of preconditioning. 6th International Symposium for Rock Fragmentation by Blasting. SAIMM, Johannesburg, 1999.
17. Rorke A. J., Brenchley P. R., Van Rensburg A. J. Preliminary Preconditioning Results Obtained at West Driefontein. COMRO Internal Report No: 548. 1989.
18. Toper A. Z. Destressing / Preconditioning to control rockbursts in South African deep-level gold mines. International Seminar on Deep and High Stress Mining. Australian Centre for Geomechanics. Perth, November 2002.
19. Lightfoot N., Kullmann D. H., Stewart R. D., Toper A. Z. Guidelines for preferable layouts for preconditioning with appropriate explosive and stemming: Revision 1. CSIR Division of Mining Technology, SIMRAC Interim Report, Project GAP 030. Nov. 1995.
20. Kullmann D. H., Stewart R. D., Lightfoot, N., Longmore P. J. Interim report on the progress towards the implementation of preconditioning as a technique for controlling face bursting on deep-level mines. CSIR Division of Mining Technology, SIMRAC Interim Report, Project GAP 030. 1995.
21. Lightfoot N., Kullmann D. H., Toper A. Z., Stewart R. D., Grodner M., Janse van Rensburg A. L., Longmore P. J. Preconditioning to reduce the incidence of facebursts in highly stressed faces. CSIR Division of Mining Technology, SIMRAC Final Report, Project GAP 030. 1996.
22. Roux A. J. A., Leeman E. R., Denkhaus H. G. Destressing: A means of ameliorating rockburst conditions, Part 1 – The conception of destressing and the results obtained from its application. Journal of SAIMM. October 1957. pp. 101–119.
23. Giltner S. G. Proposed Method of Preconditioning Stope Faces with Small Diameter Blastholes. COMRO Internal Note No: 06/92. 1992.
24. Sengani F., Zvarivadza T. Orientation of radial fractures in the vicinity of effective face perpendicular preconditioning holes. Proceedings of the 1st international conference on advances in rock Mechanics. Hammamet, Tunisia, 29–31 March 2018.
25. Sengani F., Zvarivadza T. Borehole periscope observations of rock fracturing ahead of the preconditioned mining faces in a deep level gold mine. Proceedings of the 1st international conference on advances in rock mechanics. Hammamet, Tunisia. 29–31 March 2018.
26. Cloete D. R., Jager A. J. The nature of the fracture zone in gold mines as revealed by diamond core drilling. Association of Mine Managers. Papers and Discussions. 1972–1973.
27. Adams G. R., Jager A. J. Petroscopic observations of rock fracturing ahead of stope faces in deep-level gold mines. Journal of South African Institution of Mining and Metallurgy. 1980. Vol. 6. pp. 204–209.
28. Kutter H. K. The Interaction between stress Wave and Gas Pressure in the Fracture Process of an underground Explosion with Particular Application to Presplitting. Ph. D. Thesis, University of Minnesota, 1967.
29. Persson P. A. High-speed photography of scale-model rock blasting. Proc. of the 9th Int. Congress on high-speed photography. Denver, Colorado, 1970.

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