Study of change in the physical-mechanical properties of hard rocks and their fracturing with depth using the example of the Khibiny massif

Andrey M. Kuznetsov, Maria S. Kulkova
Mining Institute of the Kola Scientific Center of the Russian Academy of Sciences, Apatity, Russian Federation
Mining Industry Journal (Gornaya Promyshlennost) №5/ 2026 p. 258-264

Summary: As the mining operations expand, the issue of the change patterns in the physical and mechanical properties of rocks and parameters of their fracturing with burial depth is becoming increasingly relevant. Information available in the published literature does not provide a clear understanding of how these characteristics vary, thereby explaining the need for field and laboratory investigations during the deposit development. This paper presents the results of a comprehensive analysis of structural fracturing and physical and mechanical properties of the core material taken from a subvertical borehole at one of the deposits within the Khibiny massif. In the interval from 340.0 to 841.0 m below the ground surface, the rock mass quality index, linear fracture frequency, density of four rock types and their uniaxial compressive and tensile strength were determined; fault structures and core discing zones were also identified. It is shown how the physical-mechanical properties of the investigated rocks and their fracturing vary with increasing burial depth.

Keywords: hard rocks, burial depth, physical-mechanical properties, fracturing, strength, density.

Acknowledgements: The authors express their gratitude to Olga Nikolaevna Tselovalnikova, Lead Technologist at Laboratory for her collaboration in the geotechnical description of the core from the test borehole and in collection of samples to identify the physical and mechanical properties of the rocks.

For citation: Kuznetsov Andrey M., Kulkova Maria S. Study of change in the physical-mechanical properties of hard rocks and their fracturing with depth using the example of the Khibiny massif. Mining Industry Journal (Gornaya Promyshlennost). 2026;(5):258–264. https://doi.org/10.30686/1609-9192-2026-5-258-264

Article info

Received: 17.05.2026

Revised: 22.06.2026

Accepted: 13.07.2026

Authors info

Kuznetsov Andrey M. – Cand. Sci. (Eng.), Head of the Labora- tory of Instrumental Study of Rock's State of the Russian Arctic Region, Department of Rock Mechanics, Mining Institute, Kola Science Centre of the Russian Academy of Sciences, Apatity, Rus- sian Federation; https://orcid.org/0000-0002-0624-4351; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Kulkova Maria S. – Cand. Sci. (Eng.), Senior Research Associate, Laboratory for Forecasting the Rockburst hazard of ore deposits, Department of Rock Mechanics, Mining Institute, Kola Science Centre of the Russian Academy of Sciences, Apatity, Russian Federation; https://orcid.org/0000-0003-4417-0223; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

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