Vol. 337 No. 3 (2026)
DOI https://doi.org/10.18799/24131830/2026/3/5097
Assessment of the chloride rock test sample shape effect on the accuracy of determining the uniaxial compressive strength
Relevance. The need to take into account the effect of the geometric parameters of the chloride rocks test samples on the accuracy of determining the tensile strength under uniaxial compression, which is critically important for ensuring the safety of mining operations at the Verkhnekamskoe potash deposit. Understanding the extent of this effect, as well as identifying and using transient dependencies between samples with different shape coefficients makes it possible to minimize errors in the design and operation of underground structures. Aim. Qualitative and quantitative assessment of the effect of the shape and ratio of linear dimensions of samples (height/diameter or height/side of a square) on the uniaxial compressive strength for two lithotypes of chloride rocks – rock salt and sylvinite – taking into account the type of cross-section (round or square). Methods. Laboratory tests for uniaxial compression using the ASIS automated complex, statistical data processing, approximation by power dependences, Results and conclusions. It was found that the dependence of the tensile strength on the relative height of the sample (h/d or h/a) is different for rock salt and sylvinite, and also depends on the type of cross-section. For sylvinite with a square section, the most significant increase in strength is observed with a decrease in h/a, while for rock salt, the obtained curves in relative strength coordinates and the ratio of linear dimensions for round and square sections are similar. It is shown that the application of generalized dependencies leads to errors of over 10%, especially when testing samples of sylvinite. Specialized formulas are proposed for recalculating strength, taking into account lithology and type of section, providing more accurate values of the strength parameter. The results of the study emphasize the need for separate consideration of the geometric parameters of the samples when testing chloride rocks to increase the reliability of geomechanical calculations.
For citation: Rysin A.I., Nurtdinov A.S., Rumyantseva N.A., Lebedeva A.M. Assessment of the chloride rock test sample shape effect on the accuracy of determining the uniaxial compressive strength. Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2026, vol. 337, no. 3, pp. 192–201. https://doi.org/10.18799/24131830/2026/3/5097
Keywords:
chloride rocks, silvinite, rock salt, tensile strength, shape coefficient, cross section shape
References:
1. Zubov V.P., Smychnik A.D. Reducing the risks of flooding in potash mines during underground water breakthroughs into mine workings. Journal of mining institute, 2015, vol. 215, pp. 29–37. (In Russ.)
2. Gromtsev K.V. Ensuring the safety of potash seam mining and preserving the integrity of the water-protective stratum. Mining informational and analytical bulletin, 2017, vol. S5-2, pp. 34–41. (In Russ.)
3. Baryakh A.A., Smirnov E.V., Kvitkin S.Yu., Tenison L.O. Russia’s potash industry: Problems of rational and safe subsoil use. Mining Industry, 2022, vol. 1, pp. 41–50. (In Russ.) DOI: 10.30686/1609-9192-2022-1-41-50.
4. Andreyko S.S., Litvinovskaya N.A. Local prediction of zones hazardous for gas-dynamic phenomena from the floor of mine workings in the AB seam in the southern part of the BKPRU-4 mine field of the Verkhnekamsk potash salt deposit. Mining informational and analytical bulletin, 2013, vol. 4, pp. 205–211. (In Russ.)
5. Andreyko S.S. Current state of gas-dynamic phenomena in operating and newly commissioned potash mines. Gornoe Ekho, 2019, vol. 2 (75), pp. 82–89. (In Russ.) DOI: 10.7242/echo.2019.2.20.
6. Lukyanets E.V., Bobrov D.A. Mechanism of gas-dynamic phenomena in folded structures of potash seams. Gornoe Ekho, 2020, vol. 2 (79), pp. 106–114. (In Russ.) DOI: 10.7242/echo.2020.2.21
7. Kopylov I.S. Geodynamically active zones of the Verkhnekamsk potassium-magnesium salt deposit and their influence on engineering-geological conditions. Modern problems of science and education, 2011, vol. 5, pp. 146–153. (In Russ.)
8. Filatov V.V., Bolotnova L.A. On the seismicity of the Verkhnekamsk potash salt deposit. News of higher educational institutions. Mining magazine, 2020, vol. 1, pp. 60–67. (In Russ.) DOI: 10.21440/0536-1028-2020-1-60-67.
9. Chaykovskiy I.I. Mechanisms of salt tectonics in the Verkhnekamsk deposit, Perm Krai. Metallogeny of ancient and modern oceans–2014. Twenty Years at the Frontline of Geology of Mineral Deposits. Scientific edition. Miass, Institute of Mineralogy UB RAS Publ., 2014. pp. 23–27. (In Russ.)
10. Chaykovskiy I.I. Typification of the main mechanisms of salt tectonics worldwide: The Verkhnekamsk deposit as a benchmark of multistage gravitational sliding. Bulletin of the Perm Scientific Center, 2013, vol. 1, pp. 18–37. (In Russ.)
11. Liang W.G., Zhao Y.S., Xu S.G., Dusseault M.B. Effect of strain rate on the mechanical properties of salt rock. International Journal of Rock Mechanics and Mining Sciences, 2011, vol. 4, pp. 161–167. DOI: 10.3724/SP.J.1235.2012.00054.
12. Liang W., Yang C., Zhao Y., Dusseault M.B., Liu J., Experimental investigation of mechanical properties of bedded salt rock. Int. J. Rock Mech, 2007, vol. 44, no. 3, pp. 400–411. DOI: 10.1016/j.ijrmms.2006.09.007.
13. Kolano M., Flisiak D. Comparison of geo-mechanical properties of white rock salt and pink rock salt in Kłodawa salt diaper. Studia Geotechnica et Mechanica, 2013, vol. 35, no. 1, pp. 119–127. DOI: 10.2478/sgem-2013-0010.
14. Zhang Z., Jiang D., Liu W., Chen J. Study on the mechanism of roof collapse and leakage of horizontal cavern in thinly bedded salt rocks. Environ. Earth, 2019, vol. 78, no. 10, pp. 292. DOI: 10.1007/s12665- 019-8292-2.
15. Liang Z.Z., Xing H., Wang S.Y., Williams D.J., Tang C.A. A three-dimensional numerical investigation of the fracture of rock specimens containing a pre-existing surface flaw. Computers and Geotechnics, 2012, vol. 45, pp. 19–33. DOI: 10.1016/j.compgeo.2012.04.011.
16. Song Y., Yang S.Q., Li K.S., Yin P.F., Shad P.Z.P. Mechanical behavior and fracture evolution mechanism of composite rock under triaxial compression: insights from three-dimensional DEM modeling. Rock Mechanics and Rock Engineering, 2023, vol. 56, pp. 7673–7699. DOI: 10.1007/s00603-023-03443-8.
17. Hao Lin, Jianfeng Liu, Jianxiong Yang, Lina Ran, Guosheng Ding, Zhide Wu, Cheng Lyu Yu Bian. Analysis of damage characteristics and energy evolution of salt rock under triaxial cyclic loading and unloading. Journal of Energy Storage, 2022, vol. 56, Part B. DOI: 10.1016/j.est.2022.106145.
18. Liang W., Zhao Y., Xu S., Dusseault M.B. The impact of soft interlayers on the mechanical behavior of bedded salt rock. Mechanical Behavior of Salt VII, 2012, pp. 23–30.
19. ASTM D4543-08 standard practices for preparing rock core as cylindrical test specimens and verifying conformance to dimensional and shape tolerances. West Conshohocken, PA, ASTM International, 2008. 9 p. DOI: 10.1520/D4543-08.
20. Kashfi M., Shad S., Zivar D. Evaluation of sample scale effect on geomechanical tests. Petroleum Research, 2022, vol. 7, pp. 527–535. DOI: 10.1016/j.ptlrs.2022.01.003.
21. SS 21153.2-84. Methods for determining uniaxial compressive strength. Moscow, Gosstandart of the USSR Publ., 1984. 8 p.
22. Rysin A.I., Tyupin V.N. Influence of the geometric shape of sylvinite samples on their uniaxial compressive strength under mining-geological conditions of the Palashersky area of the Verkhnekamsk potassium-magnesium salt deposit. Surveying and subsurface use, 2024, no. 3, pp. 67–71. (In Russ.)
23. Guidelines for protecting mines from flooding and safeguarding undermined facilities at the Verkhnekamsk potassium-magnesium salt deposit. Perm, GI Ural Branch of the Russian Academy of Sciences Publ., 2014. 130 p. (In Russ.)
