DOI: 10.21440/0536-1028-2019-6-41-50

Kozyrev A. A., Kuznetsov N. N., Fedotova Iu. V., Shokov A. N. The determination of rockburst hazard degree of hard rocks by the test results under uniaxial compression. Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal = News of the Higher Institutions. Mining Journal. 2019; 6: 41–50 (In Russ.). DOI: 10.21440/0536-1028-2019-6-41-50

Introduction. Currently the principal approach to the estimation of rock tendency to rockburst hazard consists in analyzing their complete stress-strain curve and defining the post-peak strain and energy parameters under uniaxial compression conditions. The disadvantage of such method is a need of performing the studies on specialized stiff test machines. The possibility of such machines purchasing is limited by their high prices and unit quantity of production.
Research aim. Our work is aimed at comparing the determination results of rockburst hazard in the Khibiny and Kovdor rock massifs of the Murmansk region by applying the method proposed and a method of the complete stress-strain curve analysis of hard rocks with using stiff test machines.
Methodology. Energy parameters and strain characteristics of hard rocks have been experimentally studied, parameters and characteristics of their rockburst hazard have been determined. We propose a more simple method to determine the rockburst hazard for rocks by analyzing the strain curve at a prepeak region and values of elastic energy accumulated till the compressive strength. For this we do not need the test machines with enhanced stiffness and the laboratory studies are performed on usual equipment by standard methods.
Results. Based on the studies, we determined the strain and energy parameters of the hard rocks, investigated and defined their rockburst category – rockburst hazardous or not.
Conclusions. The obtained data made it possible to conclude that the estimation results of rockburst hazard for the rocks at the pre-peak stage fully correspond to the results of estimation carried out on the basis of complete deformation curve analysis.

Key words: rockburst hazard; deformation; elastic energy; hard rocks; laboratory tests; uniaxial
compression; sample.

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Received 7 May 2019