Estimating long-term strength in salt rocks

A package of lab-scale tests of sylvinite, carnallite and rock salt sampled in mines of the Upper Kama (Verkhnekamensk) deposit were carried out, including uniaxial instantaneous and long-term compression. Using the test data, the complete diagrams of deformation and the creep curves were plotted, and the main mechanical and rheological parameters of rock salt deformation were determined. It is found how the load level affects the stationary creep rate in the test samples. A rapid method is proposed for determining long-term strength of salt rocks by plotting a theoretical curve of the long-term strength as function of the stationary creep rate. The destruction time of the test salt rock samples is defined by the critical strains at the limit of the residual strength. The use of the method allows reducing the testing time to 5–7 days. The theoretical curves of the long-term strength are plotted for all lithological types of salt rocks. For sylvinite, the long-term strength is correlated with the height-to-width ratio of the test samples. The results are used to estimate the allowable loading rate for rib pillars. It is shown that for «high» pillars, the allowable loading rate should be lower than the specified standard values.

Baryakh A. A., Udartsev A. A., Pankov I. L. Estimating long-term strength in salt rocks. MIAB. Mining Inf. Anal. Bull. 2024;(11):5-22. [In Russ]. DOI: 10.25018/0236_1493_ 2024_11_0_5.

The tests used equipment of the Material and Substance Research Shared Equipment Center at the Perm Research Center of the Ural Branch, RAS. The study was carried out within the framework of a large research project and was supported by the Ministry of Science and Higher Education of Russia, Agreement No. 075-15-2024-535 от 23.04.2024.

A.A. Baryakh¹, Dr. Sci. (Eng.), Academician of Russian Academy of Sciences, e-mail: bar@mi-perm.ru, ORCID ID: 0000-0003-2737-6166,
A.A. Udartsev¹, Junior Researcher, e-mail: udartsev@mi-perm.ru,
I.L. Pankov¹, Cand. Sci. (Eng.), Senior Researcher, e-mail: ivpan@mi-perm.ru,
¹ Mining Institute of Ural Branch, Russian Academy of Sciences, 614007, Perm, Russia.

A.A. Baryakh, e-mail: bar@mi-perm.ru.

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