Justification of cylindrical entry cut geometry in underground mine gallery

Geometry of a cylindrical entry cut in an underground mine gallery is justified using a stage-wise model of rock mass disintegration by blasting. According to this model, at the first stage, a strong blast-induced compression wave breaks the charge–rock interface (crushes and makes plastic), the explosion cavity is expanded, and the crushing zone changes into the radial fracturing zone. During this time, rock mass experiences basic disintegration, and the cylindrical explosion cavity reaches its ultimate limits. At the second stage, the gaseous explosion products (GEP) transmit accelerated motion to broken rock particles toward free surface. The third stage is fragmentation of rocks under the action of GEP and gravity, and blasted muck pile formation. The model determines the key blast parameters in the solid medium: strength characteristics of rocks under all-round explosive loading; relative limit radius of explosion cavity; radii of zones of fine crushing and radial fracturing; efficient blasting pattern design. Using these parameters, new approach to determination of the cylindrical entry cut geometry is justified. The analytical relations are obtained for designing blast patterns in faces. Based on the rational blasting pattern design, the parameters of production and perimeter blastholes are determined. The new drilling-and-blasting designs applied in underground mines of Kazakhmys Corporation made it possible to reduce explosive consumption by 8–12%, to increase broken rock yield per 1 m of borehole by 8–12%, and to ensure the desired grain size composition and the face advance. The cardinal difference of the new procedure from the known analogs is the use of the limiting explosion cavity radius as blast efficiency criterion in the solid medium, which is the first time in the mining science. This new criterion efficiently correlates the blast efficiency with the physical/mechanical properties of rocks, physicochemical characteristics of explosives, and blasting conditions.

Keywords: underground mine gallery, cylindrical entry cut, entry cut geometry, analytical determination of parameters, automated design.
For citation:

Rakishev B. R., Orynbay A. A., Musakhan A. B., Toleuov K. A. Justification of cylindrical entry cut geometry in underground mine gallery. MIAB. Mining Inf. Anal. Bull. 2021;(12):31-46. [In Russ]. DOI: 10.25018/0236_1493_2021_12_0_31.

Acknowledgements:
Issue number: 12
Year: 2021
Page number: 31-46
ISBN: 0236-1493
UDK: 622.235
DOI: 10.25018/0236_1493_2021_12_0_31
Article receipt date: 10.06.2021
Date of review receipt: 04.10.2021
Date of the editorial board′s decision on the article′s publishing: 10.11.2021
About authors:

B.R. Rakishev1, Academician of NAS of the Republic of Kazakhstan, Dr. Sci. (Eng.), Professor, e-mail: b.rakishev @mail.ru,
A.A. Orynbay1, PhD Student, Senior Lecturer, e-mail: asfa_orin@mail.ru, AUES University, Almaty, Kazakhstan,
A.B. Musakhan1, PhD Student, Junior Researcher, e-mail: a_mussakhan@yahoo.com,
K.A. Toleuov, Chief Specialist for Drilling and Blasting Operations, PA ZhCM LLP «Corporation Kazakhmys», Zhezkazgan, Kazakhstan, e-mail: kasiymhan.toleyov@kazakhmys.kz,
1 Satbayev University, Almaty, Kazakhstan.

For contacts:

B.R. Rakishev, e-mail: b.rakishev@mail.ru.

Bibliography:

1. Kutuzov B. N., Andrievskiy A. P. Novaya teoriya i novye tekhnologii razrusheniya gornykh porod udlinennymi zaryadami vzryvchatykh veshchestv: monografiya [New theory and new technologies of destruction of rocks with elongated charges of explosives: monograph], Novosibirsk, Nauka, 2002, 95 p.

2. Vokhmin S. A., Kurchin G. S., Kirsanov A. K., Gribanova D. A. Calculation of the structure of a straight prismatic cut. Modern Problems of Science and Education. 2015, no. 1-1, pp. 27. [In Russ].

3. Chandrakar S., Paul P. S., Sawmliana C. Influence of void ratio on «Blast Pull» for different confinement factors of development headings in underground metalliferous mines. Tunnelling and Underground Space Technology. 2021, vol. 108, article 103716. DOI: 10.1016/j. tust.2020.103716.

4. Salum A. H., Murthy V. M. S. R. Optimising blast pulls and controlling blast-induced excavation damage zone in tunnelling through varied rock classes. Tunnelling and Underground Space Technology. 2019, vol. 85, no. 3, pp. 307—318.

5. Dolzhikov K. I., Mangush S. K. Methodology for calculating the parameters of drilling and blasting operations when carrying out underground mine workings. Nauchnyy vestnik Moskovskogo gosudarstvennogo gornogo universiteta. 2012, no. 11, pp. 13—24. [In Russ].

6. Umarov F. Ya., Nasirov U. F., Nutfulloev G. S., Nazarov Z. S., Sharipov L. O. Increasing the efficiency of underground mine workings using borehole charges with a cumulative effect. Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal. 2020, no. 3, pp. 15—23. [In Russ].

7. Stafeev A. A., Khobta A. A. Determination of the penetration distance between parallel boreholes and boreholes in straight cuts. MIAB. Mining Inf. Anal. Bull. 2014, no. 5, pp. 362—369. [In Russ].

8. Kaplunov D. R., Yukov V. A. Changing the parameters of blasting blasting to improve the efficiency of mine pre-dressing. MIAB. Mining Inf. Anal. Bull. 2016, no. 9, pp. 172—184. [In Russ].

9. Kirsanov A. K., Vokhmin S. A., Kurchin G. S. Improving the methodology for calculating the parameters of drilling and blasting operations in the construction of horizontal and inclined mine workings on the example of the mines of the Polar Division of OJSC MMC Norilsk Nickel. Journal of Siberian Federal University. Engineering and Technologies. 2015, vol. 8, no. 4, pp. 396—405. [In Russ].

10. Kozyrev S. A., Fattakhov E. I. Computer-aided design of drilling and blasting operations during mine workings. MIAB. Mining Inf. Anal. Bull. 2007, no. S7, pp. 105—113. [In Russ].

11. Catalan A., Onederra I. Modelling of preconditioning by blasting in block and panel caving. Transactions of the Institution of Mining and Metallurgy, Section A: Mining Technology. 2016, vol. 126, no. 2, pp. 1—18. DOI: 10.1080/14749009.2016.1252556.

12. Xiu-wei Chai, Sha-sha Shi, Yao-feng Yan, Jian-guo Li, Long Zhang Key blasting parameters for deep-hole excavation in an underground tunnel of phosphorite mine. Advances in Civil Engineering. 2019, vol. 2019, article 4924382. DOI: 10.1155/2019/4924382.

13. Chakraborty A. K., Roy P. P., Jethwa J. L., Gupta R. N. Blast performance in small tunnels — a critical evaluation in underground metal mines. Tunnelling and Underground Space Technology. 1998, vol. 13, no. 3, pp. 331—339. DOI: 10.1016/S0886-7798(98)00059-5.

14. Wenbo Lu, Jianhua Yang, Ming Chen, Chuangbing Zhou An equivalent method for blasting vibration simulation. Simulation Modelling Practice and Theory. 2011, vol. 19, no. 9, pp. 2050—2062. DOI: 10.1016/j.simpat.2011.05.012.

15. Pokrovskiy G. I., Fedorov I. S. Deystvie udara i vzryva v deformiruemykh sredakh [Impact and explosion action in deformable media], Moscow, Promstroyizdat, 1957, 276 p.

16. Rakishev B. R. Prognozirovanie tekhnologicheskikh parametrov vzorvannykh porod na kar'erakh [Prediction of technological parameters of blasted rocks in open pits], Alma-Ata, Nauka, 1983, 240 p.

17. Rakishev B. R. Avtomatizirovannoe proektirovanie i proizvodstva massovykh vzryvov na kar'erakh [Computer-aided design and production of massive explosions in open pits], Almaty, Ғylym, 2016, 340 p.

18. Nikiforovskiy V. S., SHemyakin E. I. Dinamicheskoe razrushenie tverdykh tel [Dynamic destruction of solids], Novosibirsk, Nauka, 1979, 272 p.

19. Fizika vzryva. Pod red. K. P. Stanyukovicha [Explosion physics. Stanyukovich K. P. (Ed.)], Moscow, Nauka, 1975, 704 p.

20. Khanukaev A. N. Fizicheskie protsessy pri otboyke gornykh porod vzryvom [Physical processes during the breaking of rocks by an explosion], Moscow, Nedra, 1974, 223 p.

21. Adushkin V. V., Sukhotin A. P. On the destruction of a solid medium by an explosion. Prikladnaya mekhanika i tekhnicheskaya fizika. 1961, no. 4, pp. 94—102. [In Russ].

22. Rodionov V. N., Adushkin V. V., Kostyuchenko V. N. Mekhanicheskiy effekt podzemnogo vzryva [The mechanical effect of an underground explosion], Moscow, Nedra, 1971, 200 p.

23. Rakishev B. R., Rakisheva Z. B. Basic characteristics of the stages of rock massif destruction by explosive crushing. Proceedings of the 7th International Conference on Physical Problems of Rock Destruction. Beijing, China. 2011, pp. 65—69.

24. Powers L., Snell M. Microsoft Visual Studio 2015 Unleashed. 3rd edition, Indianapolis, United States: Sams, 2015, 1292 p.

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