Empress Catherine II Saint-Petersburg Mining University, Saint-Petersburg, Russia

V. V. Glazunov, Professor, Doctor of Engineering Sciences
M. M. Saitgaleev, Post-Graduate Student–Researcher, Saitgaleev_MM@pers.spmi.ru
D. N. Petrov, Associate Professor, Candidate of Engineering Sciences
A. O. Rozanov, Senior Researcher

This study investigated the process of failure of the Khibiny deposit rocks in a hydrostatic pressure chamber with acoustic emission recording. In order to solve the tasks set, MTS 815 4600 kN testing complex was used, consisting of a press system, a hydraulic pump station and a recording system. The discussed method of analyzing hypocenters of acoustic emission events allowed studying fracture at the scale of microcrack formation and tracing the evolution of the process. The coordinates of the hypocenters of acoustic emission events were calculated throughout the experiment, the process of catastrophic macro-fracture image formation was analyzed and the accompanying stresses were determined. As a result of the study, it is found that the dominant geometry of brittle rock failure is a diagonal macro-fracture. It is also determined that failure occurs not instantly but evolves over time with the development of a fracture source. The failure process analysis through location of hypocenters of acoustic emission events shows that localization of a future macro-fracture begins at the stresses equal to 0.99 of the fracture strength. The study has a significant practical importance in terms of mining safety as it aims to timely detect a critical fracture stage. The results obtained can be used to describe the multi-stage process of rock failure to identify precursors of rock bursts. To further study the development of a fracture source by stages, it is necessary to improve the quality of recording acoustic emission events and refine methods for analyzing patterns of acoustic emission hypocenters.

1. Kozyrev A. A., Savchenko S. N., Panin V. I., Semenova I. E., Rybin V. V. et al. Geomechanical processes in the geological environment of geotechnical systems and geodynamic risk management. Apatity : KNTs RAN, 2019. 431 p.
2. Shabarov A. N., Kuranov A. D., Kiselev V. A. Assessing the zones of tectonic fault influence on dynamic rock pressure manifestation at Khibiny deposits of apatite–nepheline ores. Eurasian Mining. 2021. No. 2. pp. 3–7.
3 . Tyupin V. N. Geomechanical behavior of jointed rock mass in the large-scale blast impact zone. Eurasian Mining. 2020. No. 2. pp. 11–14.
4. Onokhin F. M. Structural Features of the Khibiny Massif and Apatite–Nepheline Deposits. Leningrad : Nauka, 1975. 106 p.
5. Tryapitsyn V. M., Shabarov A. N. Recent Tectonics and Geodynamics of the Khibiny. Kostroma : Avantitul, 2007. 146 p.
6. Gospodarikov A. P., Revin I. E., Morozov K. V. Composite model of seismic monitoring data analysis during mining operations on the example of the Kukisvumchorrskoye deposit of AO Apatit. Journal of Mining Institute. 2023. Vol. 262. pp. 571–580.
7. Kotikov D. A., Tsirel S. V. Dependence of the distribution of seismic events on the location of geological faults. Rock Mechanics for Natural Resources and Infrastructure Development—Full Papers : Proceedings of the 14^th International Congress on Rock Mechanics and Rock Engineering. London : CRC Press, 2020. Vol. 6. pp. 1448–1455.
8. Daniliev S., Danilieva N., Mulev S., Frid V. Integration of seismic refraction and fractureinduced electromagnetic radiation methods to assess the stability of the roof in mineworkings. Minerals. 2022. Vol. 12, Iss. 5. ID 609.
9. Dashko R. E., Romanov I. S. Forecasting of mining and geological processes based on the analysis of the underground space of the Kupol deposit as a multicomponent system (Chukotka Autonomous Region, Anadyr district). Journal of Mining Institute. 2021. Vol. 247. pp. 20–32.
10. Kotikov D. A., Shabarov A. N., Tsirel S. V. Connecting seismic event distribution and tectonic structure of rock mass. Gornyi Zhurnal. 2020. No. 1. pp. 28–32.
11. Morozov K. V., Demekhin D. N., Bakhtin E. V. Multicomponent strain gauges for assessing the stress–strain state of a rock mass. MIAB. 2022. No. 6-2. pp. 80–97.
12. Protosenya A. G., Alekseev A. V., Verbilo P. E. Prediction of the stress–strain state and stability of the front of tunnel face at the intersection of disturbed zones of the soil mass. Journal of Mining Institute. 2022. Vol. 254. pp. 252–260.
13. Karasev M. A., Petrushin V. V., Rysin A. I. The hybrid finite/discrete element method in description of macrostructural behavior of salt rocks. MIAB. 2023. No. 4. pp. 48–66.
14. Shabarov A., Kuranov A., Popov A., Tsirel S. Geodynamic risks of mining in highly stressed rock mass. Problems in Geomechanics of Highly Compressed Rock and Rock Masses : Proceedings of the 1st International Scientific Conference. 2019. E3S Web of Conferences. 2019. Vol. 129. ID 01011.
15. Trushko V. L., Protosenya A. G. Prospects of geomechanics development in the context of new technological paradigm. Journal of Mining Institute. 2019. Vol. 236. pp. 162–166.
16. Shabarov A. N., Tsirel S. V., Morozov K. V., Rasskazov I. Yu. Concept of integrated geodynamic monitoring in underground mining. Gornyi Zhurnal. 2017. No. 9. pp. 59–64.
17. Goodfellow S. D., Flynn J. W., Reyes-Montes J. M., Nasseri M. H. B., Young R. P. Acquisition of complete acoustic emission amplitude records during rock fracture experiments. Journal of Acoustic Emission. 2014. Vol. 32.
18. Rozanov A., Petrov D., Gladyr A., Tereshkin A., Samoilov V. N. et al. Acoustic emission method of rock burst risk assessment. Proceedings of the 81st EAGE Conference and Exhibition 2019. London, 2019. Vol. 2019. DOI: 10.3997/2214-4609.201901152
19. Rozanov A., Petrov D., Gladyr A., Korchak P. Acoustic emission analysis of brittle and ductile behavior of rocks at critical stresses. Proceedings of the 82^nd EAGE Annual Conference & Exhibition. Amsterdam, 2021. Vol. 2021. DOI: 10.3997/2214-4609.202011927
20. Damaskinskaya E. E., Gilyarov V. L., Nosov Yu. G., Podurets K. M., Kaloyan A. A. et al. Defect structure formation in quartz single crystal at the early stages of deformation. Physics of the Solid State. 2022. Vol. 64, No. 4. pp. 451–457.
21. Gilyarov V. L., Damaskinskaya E. E. Modeling of fracture and acoustic emission in polycrystalline solids with the discrete elements method. Physics of the Solid State. 2022, Vol. 64, No. 6. pp. 664–669.
22. Ben-Zion Y., Dresen G. A Synthesis of fracture, friction and damage processes in earthquake rupture zones. Pure and Applied Geophysics. 2022. Vol. 179, Iss. 12. pp. 4323–4339.
23. Davidsen J., Goebel T., Kwiatek G., Stanchits S., Baró J. et al. what controls the presence and characteristics of aftershocks in rock fracture in the lab? Journal of Geophysical Research: Solid Earth. 2021. Vol. 126, Iss. 10. ID e2021JB022539.
24. Dresen G., Kwiatek G., Goebel T., Ben-Zion Y. Seismic and aseismic preparatory processes before large stick–slip failure. Pure and Applied Geophysics. 2020. Vol. 177, Iss. 12. pp. 5741–5760.