Vasyliev L.M., Vasyliev D.L., Nazarov O.Ye., Malich M.G. The analytical method for calculating ultimate compression strength of the rock cylindrical samples at pyramidal truncated type of their destruction

Details

Parent Category: Geo-Technical Mechanics, 2019

Category: Geo-Technical Mechanics, 2019, Issue 149

Geoteh. meh., 2019, 149, 142-149

https://doi.org/10.15407/geotm2019.149.142

 THE ANALYTICAL METHOD FOR CALCULATING ULTIMATE COMPRESSION STRENGTH OF THE ROCK CYLINDRICAL SAMPLES AT PYRAMIDAL TRUNCATED TYPE OF THEIR DESTRUCTION

¹Vasyliev L.M., ¹Vasyliev D.L., ¹Nazarov O.Ye., ²Malich M.G.

¹Institute of Geotechnical Mechanics named by N. Polyakov of National Academy of Sciences of Ukraine,  ²National Metallurgical Academy of Ukraine

UDC 622.831: 624.131

Language: Russian

Annotation.

One of the important informational characteristics required for controlling the stress-strain state of rocks and their effective destruction during disintegration is ultimate strength the specimens, which is determined by special presses available in a few research institutes. The mechanism of local destruction of fragile bodies and crack formation in them was disclosed. A method was developed for calculating maximum vertical stress at the crack tip. Another method was developed for calculating strength of cylindrical rock specimen with using three indices of properties, which can be easily determined experimentally in the mining enterprises, where the results of the calculation can be used immediately. One more method was developed for truncated-pyramidal samples, one of the most common forms of destruction of cylindrical rock samples, mainly of average strength at their crushing. The method is based on the laws of distribution of normal and shearing stresses, which are accepted by the Prandtl theory: shearing stresses are constant, and normal stresses are linear. The calculated values of the ultimate strength were compared with experimental ones taken from the rock cadaster. Average convergence of the rock sample ultimate strength was 86.7%. This allows the authors to recommend their method for use by mining companies for determining hardness of the rocks. Besides, the authors created an analytical model of the process of truncated-pyramidal destruction of cylindrical rock samples with using experimental values of three indices of the rock properties: shearing limit and coefficients of internal and external friction. The proposed method makes it possible to determine ultimate strength of the rock samples by using three indices of properties, which can be determined by simple experimental methods by the mining enterprises, which then can use the results of the calculation immediately for evaluating effective rock destruction at their disintegration.

Keywords:

rock; criterion; stress; ultimate strength; sample; local destruction; crack.

References

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About the authors

Vasyliev Leonyd Mykhailovych, Doctor of Technical Sciences (D. Sc), Professor, Head of the Department of Rock Breaking Problems, Institute of Geotechnical Mechanics named by N. Poyakov of National Academy of Sciences of Ukraine (IGTM, NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it. .

Vasyliev Dmytro Leonydovych, Candidate of Technical Sciences (Ph.D), Senior Researcher, Senior Researcher of the Department of Elastomersc Component Mechanics in Mining Machines, Institute of Geotechnical Mechanics named by N. Poyakov of National Academy of Sciences of Ukraine (IGTM, NAS of Ukraine), Dnipro, Ukraine.

Nazarov Oleksandr Yevheniiovych, Doctoral Student in the Department of Rock Breaking Problems, Institute of Geotechnical Mechanics named by N. Poyakov of National Academy of Sciences of Ukraine (IGTM, NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it. .

Malich Mykola Hryhoriiovych, Candidate of Technical Sciences (Ph.D), National Metallurgical Academy of Ukraine, Dnipro, Ukraine.

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