Numerical Analysis of the Borehole Pressure History and Rock Mass Damage Caused by Conventional and Power Deck Blasting

Document Type : Research - Paper

Authors

1 Ph.D Candidate, School of Mining, College of Engineering, University of Tehran, Tehran, Iran

2 Associate Professor, School of Mining, College of Engineering, University of Tehran, Tehran, Iran

3 Professor, School of Mining, College of Engineering, University of Tehran, Tehran, Iran

4 M.Sc, School of Mining, College of Engineering, University of Tehran, Tehran, Iran

Abstract

In the blast phenomenon, the explosives release a lot of energy, which causes damage and fractures the rock mass. One of the influencing parameters in the blasting results is the way the blast hole is charged. Power Deck blasting has been introduced as a blasting method to reduce or eliminate sub-drilling, optimize crushing, and reduce undesirable results. The purpose of this research is to investigate the impact of the Power Deck blasting method on the borehole pressure and damage to the rock mass compared to the conventional method. In this regard, the numerical simulation of a single blast hole was carried out using conventional and Power Deck methods by using LS-DYNA software. The results showed that in the Power Deck method, in the area of the air deck, the initial pressure of the hole is reduced compared to conventional blasting, and secondary pressures are produced, which leads to a reduction in the expansion of the hole along the air deck by 45% and increases the destruction in multi-stage. On the other hand, the generation of secondary pressures in the Power Deck method causes a 30% and 48% increase in rock mass destruction in the area of the bottom of the hole compared to the conventional method. As a result, the Power Deck blasting method improves the amount of expansion and destruction by using less explosive, which indicates the optimal use of the explosive energy.

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Main Subjects

References

  1. Hagan, T. N. (1979). “Rock breakage by explosives”. Acta Astronaut, 6(3-4): 329-340.
  2. Melnikov, N. V., and Marchenko, L. N. (1970). “Effective methods of application of explosive energy in mining and construction”. 12th Symp on Dynamic Rock Mechanics, AIME, New York, 350-378.
  3. Chiappetta, R. F., and Mammele, M. E. (1987). “Analytical high-speed photography to evaluate air decks, stemming retention and gas confinement in presplitting, reclamation and gross motion applications”. In: Proceedings of the Second International Symposium on Rock Fragmentation by Blasting, Society for Experimental Mechanics, Bethel, CT, USA, 257-301.
  4. ابراهیمی فرسنگی ،م. ع.، عسکری بدویی، م. ج.، منصوری، ح.؛ 1396؛ "کاهش هزینه‌های حفاری و انفجار در چال‌های آبدار در معدن سنگ آهن گهر زمین با استفاده از روش Power Deck". پایان نامه کارشناسی ارشد، دانشگاه شهید باهنر کرمان.
  5. Jhanwar, J. C., and Jethwa, J. L. (2000). “The use of air-decks in production blasting in an open-pit coal mine”. Geotechnical and Geological Engineering, 18: 269-287.
  6. Jhanwar, J. C., Jethwa, J. L., and Reddy, A. H. (2000). “Influence of air-deck blasting on fragmentation in jointed rocks in an open—pit manganese mine”. Engineering Geology, 57: 13-29.
  7. Correa, C. E. (2003). “Use of air-decks to reduce subdrillings in Escondida mine”. Fragblast, 7(2): 79-86.
  8. Saharan, M. R., Sazid, M., and Singh, T. N. (2017). “Explosive Energy Utilization Enhancement with Air-Decking and Stemming Plug ‘SPARSH’”. In: ISRM European Rock Mechanics Symposium EUROCK, International Society for Rock Mechanics and Rock Engineering.
  9. بخشنده امنیه، ح.، عارف مند، ا.، پورقاسمی، م.؛ 1401؛ "کنترل عقب زدگی و بهبود پارامترهای فنی و اقتصادی معدن سنگ آهن میشدوان". نشریه مهندسی منابع معدنی، دوره هفتم، شماره 1، ص 111-99.
  10. بخشنده امنیه، ح.، عارف مند، ا.، پورقاسمی، م.؛ 1399؛ "مطالعه خردشدگی حاصل از انفجار Power Deck و مرسوم در معدن سنگ آهن میشدوان". هفتمین کنفرانس مکانیک سنگ ایران.
  11. MelNikov, N. V., Marchenko, L. N., Seinov, N. P., and Zharikov, I. F. (1979). “A method of enhanced rock blasting by blasting”. IPKON ANSSSR, Moscow, Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Isko-Paemykh, Journal of Mining Science, 6: 32-42.
  12. Fourney, W. L, Barker, D. B., and Holloway, D. C. (1981). “Model studies of explosive well simulation techniques”. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 18: 113-127.
  13. Liu, L., and Katsabanis, P. D. (1996). “Numerical modeling of the effects of air decking/decoupling in production and controlled blasting”. In: Mohanty Proceeding of 5th International Conference on Rock Fragmentation by Blasting, Balkema, Rotterdam, 319-330.
  14. Lu, W., and Hustrulid, W. (2003). “A further study on the mechanism of air-decking”. Fragblast, 7(4): 231-255.
  15. Chiappetta, F. (2004). “New blasting technique to eliminate subgrade drilling, improve fragmentation, reduce explosive consumption and lower ground vibration”. Journal of Explosive Engineering, 21(1): 2-10.
  16. Lou, X., Wang, Z., Chen, B., and Yu, J. (2018). “Theoretical calculation and experimental analysis on initial shock pressure of borehole wall under axial decoupled charge”. Shock and Vibration, 2018: 7036726.
  17. Esen, S., Onederra, I., and Bilgin, H. A. (2003). “Modelling the size of the crushed zone around a blasthole”. International Journal of Rock Mechanics and Mining Sciences, 40(4): 485-495.‏
  18. Wu, L., Zhou, Y., and Guo, Z. H. (2012). “The rock failure mechanism of air-decked blasting in hole bottom”. Applied Mechanics and Materials, 201: 375-378.‏
  19. Qiu, X., Hao, Y., Shi, X., Hao, H., Zhang, S., and Gou, Y. (2018). “Numerical simulation of stress wave interaction in short-delay blasting with a single free surface”. PLOS One, 13(9): e0204166.
  20. Saadatmand Hashemi, A., and Katsabanis, P. (2020). “The effect of stress wave interaction and delay timing on blast-induced rock damage and fragmentation”. Rock Mechanics and Rock Engineering, 53: 2327-2346.‏
  21. Cheng, R., Zhou, Z., Chen, W., and Hao, H. (2022). “Effects of axial air deck on blast-induced ground vibration”. Rock Mechanics and Rock Engineering, 55: 1037-1053.
  22. Gao, F., Tang, L., Yang, C., Yang, P., Xiong, X., and Wang, W. (2023). “Blasting-induced rock damage control in a soft broken roadway excavation using an air deck at the blasthole bottom”. Bulletin of Engineering Geology and the Environment, 82(3): 97.
  23. Zhang, Z. X. (2011). “Reducing eyebrow break caused by rock blasting in Malmberget mine”. Fragblast, 5(1): 1-10.
Journal of Mineral Resources Engineering
Volume 9, Issue 4 - Serial Number 34
December 2024
Pages 81-93

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History

  • Receive Date: 08 October 2023
  • Revise Date: 10 October 2024
  • Accept Date: 18 May 2024

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