Assessment of the fracture stiffness coefficient based on laboratory testing of urtite core samples from the Khibiny massif

S.V. Dmitriev, N.N. Kuznetcov
Mining Institute of the Kola Science Centre of the Russian Academy of Sciences, Apatity, Russian Federation
Russian Mining Industry №2/ 2026 p. 200-205

Abstract: This paper presents experimental research results on normal and shear stiffness of artificial fractures in core samples collected from deposits in the Khibiny massif. Tests were carried out using the automated ASIS testing system under the constant normal load procedure. The experiments revealed dependencies of the fracture stiffness on the applied load and the core sample geometry. It was established that increasing normal stress leads to redistribution of the mechanical contact characteristics due to changes in the surface roughness and partial damage of the fracture edges. The most stable and representative data were obtained during the initial stages of loading. The average stiffness values were determined, which can serve as the input parameters for numerical modeling of the fractured rock masses, including the finite elements methods. The findings have practical relevance for assessing rock mass stability and predicting rock behavior under mining conditions.

Keywords: normal stiffness, shear stiffness, laboratory testing, stiffness coefficient, fracture, core sample

Acknowledgements: The authors express their gratitude to A.K. Pak, Senior Engineer at the Laboratory of Instrumental Investigations of Rock Mass State in the Arctic Zone of the Russian Federation, for conducting the laboratory tests.

For citation: Dmitriev S.V., Kuznetcov N.N. Assessment of the fracture stiffness coefficient based on laboratory testing of urtite core samples from the Khibiny massif. Russian Mining Industry. 2026;(2):200–205. https://doi.org/10.30686/1609-9192-2026-2-200-205

Information about the article

Received: 19.12.2025

Reviewed: 09.02.2026

Accepted: 17.02.2026

Information about the authors

Sergey V. Dmitriev – Candidate of Technical Sciences, Researcher, Mining Institute of the Kola Science Centre of the Russian Academy of Sciences, Apatity, Russian Federation; https://orcid.org/0000-0003-0422-5699; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Nikolay N. Kuznetcov – Candidate of Technical Sciences, Head of Research Sector (Laboratory), Leading Researcher, Mining Institute of the Kola Science Centre of the Russian Academy of Sciences, Apatity, Russian 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.

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