PSI - Issue 32

Artem Udartsev et al. / Procedia Structural Integrity 32 (2021) 187–193 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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According to the analysis results of the deformation rateof sylvinite and carnallite (Table 2), we can state that there is a tendency to an increase in the deformation intensity of the specimens at the stage of the steady-state creep with an increase in the lateral pressure. Fig.8 shows changes of the steady-state creep rate of sylvinite and carnallite depending on the loading degree. The analysis of the obtained data showed that the rates of the steady-state creep of carnallite exceed the similar indices of sylvinite. 5. Conclusions According to the experimental results of the conditional instantaneous compression, it was found that the ultimate strength and failure strain increase when the lateral pressure increases. In this case, the increase in the failure strain of sylvinite occurs more intensively than for carnallite. According to the results of the long-term tests, we revealed a tendency of an increase in the long-term strength of sylvinite with an increase in the lateral pressure. At the same time, the relative value of this indicator decreases with an increase of the lateral pressure. For carnallite specimens, the long-term strength set for the lateral pressure σ 3 = 5.0 MPa was 0.28 σ str . Due to a great scatter of the experimental data, it was not possible to determine the value of the long-term strength of carnallite for other levels of the lateral pressure. Analysis of the creep curves of sylvinite and carnallite revealed a tendency to an increase in the deformation rate the specimens at the stage of the steady-state creep with the increasing lateral pressure. This conclusion is consistent with the results on a decrease in the relative value of the long-term strength for sylvinite rocks with an increase in the lateral pressure. It was also found that for most loads, the rate of the steady-state creep of carnallite exceeds that of sylvinite. The research results are aimed for the geomechanical support of safe mining conditions at the Gremyachinskoye potassium salt deposit. Acknowledgments The study was performed with the financial support of the Russian Foundation for Basic Research and the Perm Kray within the Scientific Project No. 19-45-590004 and Program for Basic Scientific Researches (Project No. 0422-2019-0148-C-01). References Agnieszka Maj, 2017. Rock-Mass Movement Monitoring System in Historical Salt Mines, Using the Example of the Bochnia Salt Mine // Procedia Engineering. Vol. 191, pp. 496 – 503. DOI: 10.1016/j.proeng.2017.05.209. Baryakh A. A., Asanov V. A., Pankov I. L., 2008. Physical and mechanical properties of salt rocks of the Verkhnekamskoe potassium deposit: textbook. Perm: Publishing house of PSTPU. 199 p. Baryakh A.A., Konstantinova S.A., Asanov V.A.,1996. Deformation of salt rocks. Yekaterinburg: Ural Branch of the Russian Academy of Sciences. 203 p. Bieniawski Z. T., Bernede M. J., 1979. Suggested methods for determining the uniaxial compressive strength and deformability of rock materials: Part 1. Suggested method for determining deformability of rock materials in uniaxial compression // Int J Rock Mech Min Sci GeomechAbstr. Vol. 16, No 2, pp. 138 – 140. DOI: 10.1016/0148-9062(79)91451-7. Bolikov V.E., Konstantinova S.A., 2003. Forecast and maintenance of stability of capital mining workings. Yekaterinburg: Ural Branch of the Russian Academy of Sciences. 374 p. Kartashov Yu. M., Matveev B.V., Mikheev G.V., Fadeev A.B., 1979. Strength and deformability of rocks. M: Nedra. 269 p. Kovari K., Tisa A., Einstein H. H., Franklin J. A.,1983. Suggested methods for determining the strength of rock materials in triaxial compression: revised version // Int J Rock Mech Min Sci GeomechAbstr. Vol. 20, No 6, pp. 285 – 290. DOI: 10.1016/0148-9062(83)90598-3. Pankov I. L, Asanov V. A., Udartsev A. A., Kuzminykh V. S., 2013. Practice of using test equipment in the study of deformation and fracture of quasi-plastic rocks in laboratory conditions//Bulletin of KRSU. vol. 16, No. 1. pp.163-167. Stavrogin A.N., Tarasov B.G.,2001. Experimental physics and mechanics of rocks. SPB: Nauka. 343 p.