Numerical analysis of the impact of air column length on rock mass damage caused by air deck blasting.

Articles in Press

Document Type : Research Paper

Authors

School of Mining, College of Engineering, University of Tehran, Tehran, Iran.

10.22059/ijmge.2025.381451.595191

Abstract

In most open pit mines, the first step in the operation cycle of a mining unit is drilling and blasting. One of the most important results of blasting in mines is rock fragmentation. The dimensions of the crushed parts, resulting from the blast, are effective in the costs of loading, haulage, and crushing operations. Many studies have been done in relation to understanding the blasting mechanism and introducing different charging patterns. One of the most practical charging methods that is used today in production blasts in mines is placing an air column along the charging column. This method leads to changing blast mechanism compared to continuous charging by producing secondary pressures. In this research, the ratio of the optimal length of the air column in the limestone mass has been numerically studied in terms of rock damage. For the analysis and validation of the numerical model of the single blast hole, the field studies of other researcher have been used. In the present simulation, the length of the air column is designed between 0.3 and 0.9 meters. The results represent that by escalating the length of the air column up to 0.7 meters, the pressure applied to the stemming column and fly rock velocity increase with the rate of 1.18 and 1.3, respectively. For longer lengths, this rate increases to 1.58 and 2.39, respectively. It is caused by excessive reduction of the stemming length. The radius analysis of damage in the limestone mass around the blast hole demonstrates that the maximum damage is achieved for the air column with a length of 0.7 meters (air column length ratio is 21.9).

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References

[1] Jimeno, CL., Jimeno, EL., & Carcedo, FJA. (1995). Drilling and Blasting of Rocks. Rotterdam, Netherlands: AA Balkema.
[2] Hustrulid, W. A. (1999). Blasting Principles for Open Pit Mining., Rotterdam, Netherlands: AA Balkema.
[3] Bakhshandeh Amnieh, H., & Bahadori, M. (2017). Numerical Analysis of the Primer Location Effect on Ground Vibration Caused by Blasting. International Journal of Mining and Geo-Engineering, 51(1), 53-62. dio: https://doi.org/10.22059/ijmge.2017.62153.
[4] Berta, G. (1990). Explosive - an Engineering tool, Italesplosivi, Milano.
[5] Saadatmand Hashemi, A., & 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. Doi: https://doi.org/10.1007/s00603-019-02043-9.
[6] Melnikov, N. V., & 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.
[7] Chiappetta, R. F., & 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.
[8] Gao, F., Tang, L., Yang, C., Yang, P., Xiong, X., & 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. doi: https://doi.org/10.1007/s10064-023-03087-6.
[9] Zhang, Z. X. (2016). Rock fracture and blasting: theory and applications. Butterworth-Heinemann.
[10] Zhang, Z. X. (2011). Reducing eyebrow break caused by rock blasting in Malmberget mine. Fragblast, 1–10.
 [11] Sazid, M., & Singh, T. N. (2013). Mechanism of Air Deck technique in rock blasting –A BRIEF REVIEW. In 4th Indian Rock Conference, 29-41.
[12] 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.
[13] Rommayawes, S., Leelasukseree, C., & Jaroonpattanapong, P. (2014). Influence of Air Deck length on fragmentation in Quarry blasting. European Scientific Journal, edition vol.3 ISSN: 1857 – 788.
[14] Arefmand, E., Bakhshandeh Amnieh, H., Majdi, A. & Vahidi, M. (2024). Numerical Analysis of Borehole Pressure History and Rock Mass Damage Induced by Conventional and Air Deck Explosion Methods. Journal of Mineral Resources Engineering, 9(4), 81-93. https://doi:10.30479/jmre.2024.19413.1668.
 
[15] Mel’Nikov, N. V., Marchenko, L. N., Zharikov, I. F., & Seinov, N. P. (1979). A method of enhanced rock breaking by blasting. Soviet Mining, 15(6), 565-572.
[16] Fourney, W.L, Barker, D.B., & Holloway, DC. (1981). Model studies of explosive well simulation techniques. Int J Rock Mechs Min Sci Geomech Abs, 18,113–127.
[17] Liu, L., & Katsabanis, P.D. (1996). Numerical modeling of the effects of air decking/decoupling in production and controlled blasting. In Proceeding 5th international conference on rock fragmentation by blasting. A. A. Balkema, Rotterdam. 319–330.
[18] Lu, W., and Hustrulid, W. (2003). A further study on the mechanism of air-decking. Fragblast 7(4), 231–255. dio: http://dx.doi.org/10.1076/frag.7.4.231.23532.
[19] Lou, X., Wang, Z., Chen, B., & Yu, J. (2018). Theoretical calculation and experimental analysis on initial shock pressure of borehole wall under axial decoupled charge. Shock and Vibration. https://doi.org/10.1155/2018/7036726.
[20] Mead, D.J., Moxon, N.T., Danell, R.E., & Richardson, S.B. (1993). The use of air-decks in production blasting. In: Proceedings of the 19th annual conference on explosives and blasting technique, international society of explosives engineers, Cleveland, Ohio, USA, 437–443.
[21] Saharan, M. R., Sazid, M., & Singh, T. N. (2017). Explosive energy utilization enhancement with air-decking and stemming plug,‘SPARSH’. Procedia engineering, 191, 1211-1217. ‏dio:http://creativecommons.org/licenses/by-nc-nd/4.0/.
[22] Chen, ZB., Cheng, LY., Zhong, MS., Xu, QJ., Wen, ZL. & Sun, F. (2017). Bottom inert medium in deck charging blasting experiment. Eng Blasting, 23(1):12–15. https://doi.org/10.3969/j.issn.1006-7051.2017.01.003
 [23] Balakrishnan, V., and Pradhan, M. (2018). Explosive consumption reduction by introducing hollow plastic tubes in explosive column. APRN Journal of Engineering and Applied Sciences. 13(14), 4325-4330.
[24] Jang, H., Handel, D., Ko, Y., Yang, H. S., & Miedecke, J. (2018). Effects of water deck on rock blasting performance. International Journal of Rock Mechanics and Mining Sciences, 112, PP. 77-83. https://doi.org/10.1016/j.ijrmms.2018.09.006‏.
 [25] Bakhshandeh Amnieh, H., Arefmand, E., and Porghasemi Saghand, M. (2019). Controlling Backbreak and Improving Technical and Economic Parameters in Mishdovan Iron Ore Mine. Mineral Resources engineering. https://doi.org/10.30479/jmre.2019.10436.1251.
 [26] Bakhshandeh Amnieh, H., Arefmand , E., and Porghasemi Saghand, M. (2020). A study of rock fragmentation caused by Power Deck and conventional blasting in Mishdovan iron ore mine. 7th Iranian Rock Mechanics Conference (IRMC7),Tehran, Iran.
 [27] Cheng, R., Zhou, Z., Chen, W., & Hao, H. (2022). Effects of axial air deck on blast-induced ground vibration. Rock Mechanics and Rock Engineering,1-17. doi: https://doi.org/10.1007/s00603-021-02676-9.
[28] Zhang, GJ. (1996). A study of free toe-space explosive loading and its application in open pit blasts. In: Proceedings of 5th international symposium on rock fragmentation by blasting, 313–318.
[29] Jhanwar, J.C., & Jethwa, J.L. (2000). The use of air-decks in production blasting in an open pit coal mine. Geotech Geol Eng 18:269–287. Doi: https://doi.org/10.1023/A:1016634231801.
[30] Jhanwar, J.C., Jethwa, J.L., & Reddy, A.H. (2000). Influence of air-deck blasting on fragmentation in jointed rocks in an open pit manganese mine. Eng Geol 57:13–29. doi: https://doi.org/10.1016/S0013-7952(99)00125-8.
[31] Jhanwar, J. C. (2011). Theory and practice of air-deck blasting in mines and surface excavations: a review. Geotechnical and Geological Engineering, 29(5), 651-663. Doi: https://doi.org/10.1007/s10706-011-9425-x‏.
[32] Saqib, S., Tariq S. M., & Ali, z. (2015). Improving rock fragmentation using airdeck blasting Technique, Pak. J. Engg. & Appl. Sci, Vol. 17, 46-52.
[33] Singh, T. N., Sazid, M., & Saharan, M. R. (2012). A study to simulate air deck crater blast formation-a numerical approach. In ISRM International Symposium-Asian Rock Mechanics Symposium (pp. ISRM-ARMS7). ISRM.
[34] Qiu, X., Hao, Y., Shi, X., Hao, H., Zhang, S., & Gou, Y. (2018). Numerical simulation of stress wave interaction in short-delay blasting with a single free surface. PLOS one, 13(9), e0204166. doi: https://doi.org/10.1371/journal.pone.0204166
International Journal of Mining and Geo-Engineering

Articles in Press, Accepted Manuscript
Available Online from 07 July 2025

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