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Vol. 22 (2019 year), No. 1, DOI: 10.21443/1560-9278-2019-22-1

Kozyrev A. A., Kasparyan E. V., Fedotova Yu. V., Kuznetcov N. N.
Estimating the rockburst hazard of hard rocks based on laboratory test results

The relevance of the problem under study is based on the fact that dynamic fractures of mine workings occur in rock masses when developing mineral deposits. Safety assurance of mining depends on the awareness of proneness of various rock types to brittle failure. By now, experimental methods have been elaborated to determine rock deformation and strength properties under various loading conditions. A common drawback of the approaches in use is that they do not expressly consider the main condition of dynamic rock fracture – rock mass ability to accumulate energy when loaded. The studies have been conducted to analyze the nature of elastic energy accumulation during loading and deformation of samples of various rocks under uniaxial compression to estimate the degree of their rockburst hazard. The approach is original as it studies the deformation curve of rocks at the pre-peak stage that may be obtained with any standard equipment without the use of special-purpose test ("rigid") devices. Results of the studies conducted on standard test devices have allowed the authors to identify two different deformation patterns for the rock type tested with further establishment of criteria of rock classification by the degree of proneness to dynamic fractures. This approach is of practical value as it specifies the geomechanics zoning method of the rock mass and improves the assessment of rockburst hazard degree of specific areas at deposits being developed

(in Russian, стр.11, fig. 5, tables. 1, ref 24, Adobe PDF, Adobe PDF 0 Kb)

Vol. 26 (2023 year), No. 2, DOI: 10.21443/1560-9278-2023-26-2

Kuznetcov N. N., Kondrashov L. Yu.
Rockburst hazard potential assessment of rocks of the Khibiny massif deposits according to the Kaiser criterion

The mining and geological conditions in the mines worsen due to changes in the stress-strain state of rock masses and their structural disturbance when mining goes to great depths. Under such conditions, it is necessary to assess the impact hazard of ores and rocks that make up the mined deposits. For the prompt implementation of such an assessment, it is proposed to use the Kaiser criterion consisting in the analysis of experimental data obtained on rock samples. The paper presents the results of laboratory testing of rock samples from the deposits of the Khibiny massif under uniaxial compression and tension. The values of their brittleness coefficients have been determined. The possibility of using the Kaiser criterion for a preliminary assessment of rock burst hazard potential has been shown. It has been established that spotty-trachytoid melteigite and trachytoid ijolite-melteigite have a high potential for impact hazard, while spotted apatite-nepheline ore does not have such a potential. A comparison has been made of the obtained results of rockburst hazard assessment of hard rocks from the Khibiny massif deposits according to the Kaiser criterion, as well as the criterion of the Mining Institute of the KSC RAS and the criterion of A. N. Stavrogin. It can be noted that the Kaiser criterion makes it quite easy to carry out a preliminary assessment of rock burst hazard based on the results of testing samples on standard presses. However, to increase the degree of reliability of the data obtained, they must be certified according to the criterion of the Mining Institute of the KSC RAS or the criterion of A. N. Stavrogin.

(in Russian, стр.10, fig. 5, tables. 2, ref 16, AdobePDF, AdobePDF 0 Kb)