PSI - Issue 32

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Sci nceD rect Structural Integrity Procedia 00 (2021) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000 – 000

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Procedia Structural Integrity 32 (2021) 109–116

© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XXIIth Winter School on Continuous Media Mechanics” Abstract Increased mining depths entail both increased rock pressures and complicated rock mass structures. When it comes to mining mineral salts, there is a significant difference in the strength and deformation properties of rocks developed in the geological section, which affects the nature of deformation and the destruction of underworked strata. During the initial development stage of the Gremyachinskoye deposit, where the mining of potash salts at depths of more than 1,000 meters has been planned, a mathematical model of the undermined mass has been developed, reflecting the main features of its geological structure and the design parameters of a pillar mining system. The mathematical modelling estimated safe conditions of undermining the waterblocking strata and the expected deformations at the earth’s surface. This was carried out with an elastic -plastic plane formulation using the finite element method. The time factor was accounted for based on the developed modification of the method of alternating deformation moduli. Based on the mathematical modelling performed, it was shown that geomechanical models of new deposits of potash salts being prepared for development can be calibrated using the information available from analogous deposits; this information can be subsequently corrected, reflecting certain differences in the geological structure and parameters of the mining system. Based on the numerical modelling results, an increase in the boundary angle of the subsidence trough of the earth’s surface was established due to the significant depth of mining and the presence of hard rock strata in the geological section, which allowed the linear dimensions of the protective pillars under critical facilities to be reduced, alongside minimising losses of potash ore. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer- review under responsibility of the scientific committee of the XXIIth Winter School on Continuous Media Mechanics” Keywords:deep level;potash mining;mathematical modeling;contact elements;deformation process. XXIIth Winter School on Continuous Media Mechanics Deformations and fracture of rock strata during deep level potash mining A.A. Baryakh, A.K. Fedoseev, S.Yu. Lobanov* Mining Institute of the Ural Branch of the Russian Academy of Science, 78-a, Str. Sibirskaya, Perm, 614007, Russia Abstract Increased mining depths entail both increased rock pressures and complicated rock mass structures. When it comes to mining min ral salts, there is a significan d fference in the strength deformation propertie of rocks developed in th geological section, which aff ct the nature of e ormation and the des ruction o underworked strata. During th initial developm nt stage of he Gremyachinskoy deposit, where the mini g of potash salts at depths of more han 1,000 meters has b en pla ned, a ma matical model f the undermined mass has been developed, reflecting the main f atures of its g ologic l structure a d the design parameters of a pillar mining sy tem. Th mathematical modelling estimat d safe conditi ns of undermini g waterblocking st ata and the expected defor ations at the e r h’s surface. This was carried out w h an elastic -plastic plan formulation using he fini e elem nt meth d. The time factor wa accounted for b ed on the developed mod fication of th method of alter ating deformation moduli. Based on the mathem tical mod lling performed, it was shown that geomechanical odels new deposits of potash salts being prepared for dev lopment can be calib ated using the inf rma ion available from analogous d posits; thi information can be subs qu ntly corrected, r fle ti g certa n differences in the geological structure and parameters of the mining system. Based on the num rical modelling r sults, an increase in the bou dary angle of the subsidence trough of the earth’s surface was established due to the significa t d pth of mi ing and the prese ce of hard rock strata in th geological s ction, which allo ed the linear dim nsions of the pro ective pillars u der cri ical faciliti s to be reduced, longsid minim sing losses of potash re. © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer- review under responsibility of h scientific committe of the XXIIth Winter School on Continuous Media Mechanics” K ywords:deep level;potash mining;mathematical modeling;contact elements;deformation process. XXIIth Winter School on Continuous Media Mechanics Deformations and fracture of rock strata during deep level potash mining A.A. Baryakh, A.K. Fedoseev, S.Yu. Lobanov* Mining Institute of the Ural Branch of the Russian Academy of Science, 78-a, Str. Sibirskaya, Perm, 614007, Russia

* Corresponding author. Tel.:+7-342-225-0050; fax: +7-342-216-7502. E-mail address: LSerg@Mi-Perm.ru * Corresponding author. Tel.:+7-342-225-0050; fax: +7-342-216-7502. E-mail address: LSerg@Mi-Perm.ru

2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under res ponsibility of the scientific committee of the XXIIth Winter School on Continuous Media Mechanics” 2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review u der res ponsibility of t scientific committe of the XXIIth Winter School on Continuous Media Mechanics”

2452-3216 © 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the XXIIth Winter School on Continuous Media Mechanics” 10.1016/j.prostr.2021.09.016