A. A. B. Project (Yerevan, Armenia)

G. A. Agaronyan, Head of Drilling and Blasting, Candidate of Engineering Sciences

National Polytechnic University of Armenia (Yerevan, Armenia)

I. S. Avanesova, Candidate of Engineering Sciences, Associate Professor, inna.avanesova.1969@mail.ru

It is known that controllable and uniform fragmentation of rocks in blasting in inhomogeneous media depends mostly on the correct choice of a blast pattern. It is justified that the estimate of the change in a blasting stress wave (absorption and attenuation of elastic waves) at an interface of two inhomogeneous media, depending on the blasthole diameter, type of explosive and acoustic impedance of rock mass, is the basic requirement for the correct choice of a blast pattern. It is shown that during blasting in a jointed medium: the role of the stress wave in the process of fracture increases with the decrease in the number and width of joints; expanding gases of an explosion actively participate in the process of fracture with the increase in the number of joints; intensive absorption of the blast energy takes place in the presence of joints wider than 0.05 m. It is found that in blasting in rock masses composed of large blocks, the stress wave takes a master part in the blast-induced fracture process. The use of large-diameter blastholes in rock masses composed of medium-size and large block increases the zone of fracturing between the blastholes. When the acoustic impedance of filler decreases, absorption of the elastic waves in rock mass lowers and, consequently, the stress wave amplitude increases, i.e. the blast-induced shattering effect grows. The method is proposed to determine the blasthole diameter and the spacing of the interacting blastholes depending on the type of explosive and on the natural factors intrinsic to rock mass being blasted. The use of the recommended parameters of drilling and blasting leads to a decrease in the yield of oversize by 2 times.

1. Mosinets V. N., Abramov A. V. Destruction of Fissured and Disturbed Rocks. Moscow : Nedra, 1982. 248 p.
2. Singh S. K., Banerjee B. P., Lato M. J., Sammut C., Raval S. Automated rock mass discontinuity set characterisation using amplitude and phase decomposition of point cloud data. International Journal of Rock Mechanics and Mining Sciences. 2022. Vol. 152. ID 105072.
3. Sanchidrán J. A., Segarra P., Ouchterlony F., Gómez S. The Influential Role of Powder Factor vs. Delay in Full-Scale Blasting: A Perspective Through the Fragment Size-Energy Fan. Rock Mechanics and Rock Engineering. 2022. Vol. 55, Iss. 7. pp. 4209–4236.
4. Khorzoughi M. B., Hall R., Apel D. Rock fracture density characterization using measurement wile drilling techniques. International Journal of Mining Science and Technology. 2018. Vol. 28, Iss. 6. pp. 859–864.
5. Zhang Z.-X., Sanchidrián J. A., Ouchterlony F., Luukkanen S. Reduction of Fragment Size from Mining to Mineral Processing: A Review. Rock Mechanics and Rock Engineering. 2023. Vol. 56, Iss. 1. pp. 747–778.
6. Agaronyan G. A., Agaronyan A. G. Study of the effect of strength features and structural features of the massif on the efficiency of explosive works in quarries. Vestnik Natsionalnogo politekhnicheskogo universiteta Armenii. Metallurgiya, materialovedenie, nedropolzovanie. 2019. No. 2. pp. 104–115.
7. Kryukov G. M. Physics of Rock Fracture in Drilling and Blasting : Textbook. Moscow : Gornaya kniga, 2006. Vol. 1. 330 p.
8. He C., Yang J. Experimental and numerical investigations of dynamic failure process in rock under blast loading. Tunneling and Underground Space Technology. 2018. Vol. 83. pp. 552–564.
9. Orlenko L. P. Physics of Explosion and Shock : Tutorial. 3rd revised edition. Moscow : Fizmatlit, 2017. 400 p.
10. Kazakov N. N., Viktorov S. D., Shlyapin A. V., Lapikov I. N. Rock Fragmentation by Blasting at Open Pit Mines. Moscow : RAN, 2020. 520 p.
11. Kaixing W., Bin W., Yishan P., Khmelinin A. P., Chanyshev A. I. Experimental Investigation of Block Fracture Influence on P-Wave Propagation in Block Rock Mass. Journal of Mining Science. 2024. Vol. 60, No. 2. pp. 210–219.
12. Agaronyan G. A. A new technology for regulating actions of energy of mass explosion at the open pits. Izvestiya Natsionalnoy akademii nauk Armenii i Natsionalnogo politekhnicheskogo universiteta Armenii. Seriya tekhnicheskikh nauk. 2021. Vol. 74, No. 3. pp. 278–289.
13. Paramonov G. P., Kovalevskiy V. N., Mysin A. V. Impact on the rock massif of borehole charges with different designs. Vzryvnoe delo. 2019. No. 122/79. pp. 106–120.
14. Roy M. P., Mishra A. K., Agrawal H., Singh P. K. Blast vibration dependence on total explosives weight in open-pit blasting. Arabian Journal of Geosciences. 2020. Vol. 13, Iss. 13. DOI: 10.1007/s12517-020-05560-y
15. Overchenko M. N., Mozer S. P., Tolstunov S. A., Belin V. A. Design of control elements for emulsion explosive energy with programmable initiation. MIAB. 2020. No. 2. pp. 92–100.
16. Latyshev O. G., Kazak O. O. Physics of Rock Fracture in Drilling and Blasting. Moscow ; Vologda : Infra-Inzheneriya, 2024. 240 p.
17. Bondarenko I. F., Zharikov S. N., Syryanov I. V., Shemenev V. G. Drilling and Blasting at Kimberlite Mines in Yakutia. Yekaterinburg : IGD UrO RAN, 2017. 172 p.
18. Efremov E. I. Control of dimensions of overmilling zones in rock in blasting. Vestnik Krivorozhskogo tekhnicheskogo universiteta. 2007. Vol. 18. pp. 36–39.