Belgorod State University, Belgorod, Russia:

V. N. Tyupin, Professor, Doctor of Engineering Sciences, tyupinvn@mail.ru
V. V. Khaustov, Professor, Doctor of Geological and Mineralogical Sciences

Transbaikal State University, Chita, Russia:

E. T. Voronov, Professor, Doctor of Engineering Sciences

Generalization of the abundant experimental and theoretical research accomplished by Russian and foreign scientists in the 20^th–21^st centuries enables distinguishing between a few action zones of blasting, namely, crushing zone (fine grain crushing), radiating cracking zone, induced-fracture zone, shaking zone (residual stress after blasting), and blast-induced load zone. In the crushing zone, overgrinding takes place, which has an adverse influence on efficiency of processing of uranium, for instance, or granular quartz. The radiating cracking zone size in blasting in fractured rock masses governs the quality of drilling and blasting. The induced-fracture zone determines stability of rock mass and, consequently, safety of production processes both in surface and underground mines. In the shattering zone, fractured rock mass experiences residual stresses, which induces new fractures and rock falls, or dynamic events due to lithostatic pressure in rockburst-hazardous rock mass. This article aims at the experimental and theoretical determination of geometrics of blast-induced impact zones in different geological and geotechnical conditions with a view to developing appropriate actions toward abatement of the adverse effect exerted by these zones on geomechanical and technological processes in the course of mining. The theoretical formulas are given for the radii of the crushing, radiating cracking, induced fracturing and residual stress zones. Reliable applicability of the formulas in actual mining is proved by comparison of the calculations with the full-scale testing data. To mitigate the crushing zone impact, it is possible to charge the wellhead interval with a radial air gap, which decreases density of charging. Arrangements toward reduction of the zones of induced-fractures and residual stresses are proposed. Energy of the man-mane zone of residual stresses after blasting can be targeted at activation of raise driving with raise borer 2KV.

1. Pokrovskiy G. I., Fedorov M. S. Effects of shock and blast in deformable media. Moscow : Promstroyizdat, 1957. 276 p.
2. Feshchenko A. A., Eristov V. S. Perimeter control blasting in waterworks construction. Moscow : Energiya, 1972. 119 p.
3. Kutuzov B. N. Methods of blasting operations : Textbook. 3^rd ed. Moscow : Gornaya kniga, 2018. Vol. 1. Blast destruction of rocks. 476 p.
4. Mosinets V. N., Abramov A. V. Destruction of fissured and disturbed rocks. Moscow : Nedra, 1982. 248 p.
5. Adushkin V. V., Spivak A. A. Underground blasts. Moscow : Nauka, 2007. 578 p.
6. Kutuzov B. N., Tyupin V. N. Determination of damage zones induced by blasting in jointed rock mass. Izvestiya vuzov. Gornyi zhurnal. 1983. No. 4. pp. 53–58.
7. Typin V. N. Blasting and Geomechanical Processes in High-Stress Fractured Rock Mass. Belgorod : ID Belgorod NIU BelGU, 2017. 192 p.
8. Rakishev B. R. Prediction of process-dependent parameters in blasted rocks in open pit mines. Alma-Ata : Nauka, 1983. 239 p.
9. Vokhmin S. A., Kurchin G. S., Kirsanov A. K., Shigin A. O., Shigina A. A. Destruction of rock upon blasting of explosive agent. Journal of Engineering and Applaied Sciences. 2017. Vol. 12, No. 13. pp. 3978–3986.
10. Ghiasi M., Askarnejad N., Dindarloo S. R., Shamsoddini H. Prediction of blast boulders in open pit mines via multiple regression and ar tificial neural networks. International Journal of Mining Science and Technology. 2016. Vol. 26, Iss. 2. pp. 183–186.
11. Li-Yun Yang, Chen-Xi Ding. Fracture mechanism due to blast-imposed loading under high static stress conditions. International Journal of Rock Mechanics and Mining Sciences. 2018. Vol. 107. pp. 150–158.
12. Xiang Xia, Haibo Li, Jingtao Niu., Jianchun Li, Yaqun Liu. Experimental study on amplitude change of blast vibrations through steps and ditches. International Journal of Rock Mechanics and Mining Sciences. 2014. Vol. 71. pp. 77–82.
13. Poluhin O. N., Petin A. N., Ignatenko I. M., Dunaev V. A., Konovalov A. V. Assessment of the size of rocks in benchs and lumpiness of the blasted mountain mass on pits with use of GIS Geomix. International Journal of Pharmacy & Technology. 2016. Vol. 8, Iss. 4. pp. 26809–26818.
14. Tyupin V. N., Svyatetskiy V. S. Capacity raising of machinery rates of uranium ore bulk in conducting blasting in band delivery. Sovremennye tekhnologii. Sistemnyi analiz. Modelirovanie. 2011. No. 3(31). pp. 158–161.

15. Sokolov I. V., Smirnov A. A., Rozhkov A. A. Explosive breaking of quartz by concentrated charges in underground mining. GIAB. 2017. No. 10. pp. 178–185.
16. Ignatenko I. M., Yanitsky E. B., Dunaev V. A., Kabelko S. G. Jointing of rock mass in open pit at the Zhelezny mine of the Kovdor Mining and Processing Plant. Gornyi Zhurnal. 2019. No. 10. pp. 11–15. DOI: 10.17580/gzh.2019.10.01.
17. Aksenov A. A., Ozhiganov I. A., Gubanov D. V. The use of pressings-in method with MHS device in order to determine geomechanical state of massif and its physico-mechanical properties. Izvestiya vuzov. Gornyi zhurnal. 2015. No. 6. pp. 17–22.
18. Galaov R. B., Kisel A. A., Andreev A. A., Zubkov V. V. Pre-stoping assessment of stress state of ore body S-2 in Skalistaya Mine. Gornyi Zhurnal. 2016. No. 7. pp. 10–14. DOI: 10.17580/gzh.2016.07.02
19. Eremenko A. A., Shaposhnik Yu. N., Filippov V. N., Konurin A. I. Development of scientific framework for safe and efficient geotechnology for rockburst-hazardous mineral deposits in Western Siberia and the Far North. Gornyi Zhurnal. 2019. No. 10. pp. 33–39. DOI: 10.17580/gzh.2019.10.03
20. Volarovich M. P., Bayuk E. I., Levykin A. I., Tomashevskaya I. S. Physical and mechanical properties of rocks under high pressures and temperatures. Moscow : Nauka, 1974. 222 p.