№74-1

Determination of the influence of the degree of fracturing of the rock mass on the index of reduction of its strength

M. Beltek¹, O. Frolov¹

¹ National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute», Kyiv, Ukraine

Coll.res.pap.nat.min.univ. 2023, 74:7-18

https://doi.org/10.33271/crpnmu/74.007

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ABSTRACT

Purpose. The purpose of research of the presented scientific publication is to establish the regularity of changes in the generalized coefficient of strength reduction of disturbed rock massif depending on the degree of rock fracturing.

Research methodology. To solve the set tasks we applied a complex approach, which consists in the analysis and generalization of previous studies on the study of the change in the strength of the rock massif depending on the degree of fracturing, scientific and technical justification of the possibility of generalizing the studied strength indicators of the disturbed massif, approximation of graphs of the change in the structural weakening coefficient, RQD and RMR depending on the fracture modulus.

Research results. Scientific data of domestic scientists on determining the value of the structural weakening coefficient depending on the factors affecting the overall strength of the rock massif, and foreign scientists on establishing indicators of the state of disturbed rock massifs have been analyzed.
To summarize the results of the presented assessment methods, the changes in the structural weakening coefficient, RQD and RMR indices depending on the fracture modulus of the rock massif are combined in one graph. Alignment of the mentioned graphical dependences showed the identical character of their changes.  The curve of approximation (trend) for graphical dependences of the structural weakening coefficient, RQD and RMR on the fracture modulus, which can be described by a polynomial of the 3rd degree, has been obtained and the value of approximation reliability R²= 0.8975 has been established.

Scientific novelty. The idea of methods and indicators for assessing the state of disturbance of rock massifs depending on various factors has been developed. The analytical dependence of the change of the generalized coefficient of strength reduction of a rocky rock massif on the fracture modulus has been obtained.

Practical significance. The established influence of rock fracture modulus on the degree of strength reduction of rock massif allows to determine reliable data on the condition of ledges and sides of the quarry and to develop organizational and technical measures for further development of technology of their mining.

Keywords: rock massif, structural weakening coefficient, fracturing, rock, strength, strength limit, rock massif disturbance index, fracture modulus.

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