Loading of rib pillars in multiple seam mining at the Upper Kama salt deposit

The load estimation procedure for rib pillars uses the methods of mathematical modeling to find a normalized value of shear stress intensity in the center of vertical pillar section. As distinct from the standard procedure by Turner–Shevyakov, the new approach is unlimited by simple options of an open stoping system (single seam mining, flat lying seam, canonically shaped pillars) and is applicable in complex geotechnical situations. The article describes implementation of the calculation as a case-study of two sylvinite seams in cases of in-line and off-line arrangement of stopes. It is found that in the in-line stoping in mining of two sylvinite seams, the Turner–Shevyakov formula produces generally lower estimates of loading of rib pillars. The underestimation level depends on the thickness of the seam parting and on the size ratio of stopes in both working seams. In the off-line arrangement of stopes, the Turner–Shevyakov procedure, vice versa, gives essentially overestimated loading of rib pillars when the seam parting is less than 4 m thick as the procedure neglects unloading of the pillars, especially in undermining. Formally, the research findings demonstrate feasibility of increased extraction of ore in case of the off-line stoping but need a comprehensive geomechanical validation because of the hazard of caving of the upper working seam pillar to the stoping void of the lower working pillar.

Baryakh A. A., Lomakin I. S., Samodelkina N. A., Tenison L. O. Loading of rib pillars in multiple seam mining at the Upper Kama salt deposit. MIAB. Mining Inf. Anal. Bull. 2023;(1):5-19. [In Russ]. DOI: 10.25018/0236_1493_2023_1_0_5.

The study was supported by the Russian Science Foundation, Grant No. 19-77-30008.

A.A. Baryakh¹, Dr. Sci. (Eng.), Аcademician of Russian Academy of Sciences, e-mail: bar@Mi-Perm.ru, ORCID ID: 0000-0003-2737-6166,
I.S. Lomakin¹, Cand. Sci. (Eng.), Researcher, e-mail: Lomakin@Mi-Perm.ru, ORCID ID: 0000-0001-9852-351X,
N.A. Samodelkina¹, Cand. Sci. (Eng.), Leading Researcher, e-mail: Samodelkina@Mi-Perm.ru
L.O. Tenison, Cand. Sci. (Eng.), Head Department, Uralkali, Berezniki, Russia, e-mail: Lyudmila.Tenison@uralkali.com,
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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