Analytical method for calculating and charting “stress–deformation” provided longitudinal form of destruction of rock samples
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- Category: Geotechnical and mining mechanical engineering, machine building
- Last Updated on 24 July 2017
- Published on 24 July 2017
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Authors:
L.M.Vasiliev, Dr. Sc. (Tech.), Prof., Institute of Geotechnical Mechanics. N. S. Polyakova National Academy of Sciences of Ukraine, Dnipro, Ukraine, e‑mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
D.L.Vasiliev, Cand. Sc. (Tech.), Institute of Geotechnical Mechanics. N. S. Polyakova National Academy of Sciences of Ukraine, Dnipro, Ukraine, e‑mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
M.G.Malich, Cand. Sc. (Tech.), Assoc. Prof., National Metallurgical Academy of Ukraine, Dnipro, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
O.O.Anhelovskyi, Cand. Sc. (Tech.), Public Joint Stock Company “Krasnodonugol”, Krasnodon, Ukraine, e-mail: Aleksandr Angelovskii@krasnodon cool.com
Abstract:
Purpose. Disclosure of the formation mechanism of limiting the deformation of rock samples provided their longitudinal form of destruction.
Methodology. Methods are based on the solving the problem of destruction of rock samples on the basis of Coulomb strength criterion, an improved view of the contact friction. An analytical method has been developed for calculating the limit strength of the sample knowing three experimental indices of rock properties: shear strength of the material, coefficients of internal friction and contact friction and geometrical parameters of peaks in the sample cracks. On the basis of the developed method we determine the specific stress on the sample still under the load in the process of development of cracks. Knowing coordinate values of one or two cracks of the sample at any given moment load-carrying part is determined which is equal to the original area minus the last part, which appeared from under the load. Knowing the limit specific stress on the carrier part of the sample, the amount of deformation that corresponds to the limit specific stress with respect to the magnitude of the initial area is determined by Hooke’s law.
Findings. An analytical method is developed for calculating and charting “stress-deformation” of rock samples in their longitudinal form destruction and the mechanism of formation of this form is revealed.
Originality. For the first time the mechanism of self-organization by Bridgman paradoxical form of destruction has been disclosed and the method for constructing the “stress–deformation” chart has been given. The longitudinal form of the destruction is self-organized by internal and contact friction, in accordance with the generalized Coulomb strength criterion, which takes into account the contact friction, and local mechanics limit state of the material at the crack peak.
Practical value. Accessibility of calculating and charting “stress–deformation” on the basis of three parameters: limits shear strength of the material, coefficients of internal and contact friction as well as elasticity modulus of the material do not require involving complicated pressure equipment any more, but can be identified in the laboratory production companies where information on indicators of rock strength can be efficiently used.
References.
1. Vasiliev, L.M. and Vasiliev, D.L., 2015. The account of contact friction in the problem of rock destruction by compression. Physico-technical problems of mining, 3, pp. 48‒56.
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