Safety assessment of undermining of waterproof pillar by the Krasniy-II layer in complex mining and geological conditions of the Verkhnekamsk salt deposit

Based on the experience of mining sylvinite formations at the Durymansky, Balakhontsevsky and Palashersky sites of the Verkhnekamsk salt deposit, it was established that in complex mining and geological conditions, premature collapse of roof rocks and accelerated deformation of interchamber pillars occur, which limits the timing and completeness of filling material application. An assessment of the effect of the chamber mining system on the safety of the waterproof pillar under such mining and geological conditions showed a high probability of exceeding the main safety criteria. To improve safety, parameters of a chamber mining system with increased interchamber pillars in accordance with the Turner–Shevyakov method, and not requiring the introduction of backfill material, were proposed. Based on the experience of mining with the leaving of pliable pillars, parameters of a chamber mining system with the leaving of a softening zone along the constant boundaries of the mined-out space were determined. Taking into account world experience, parameters of alternative mining systems were considered and determined, namely, a chamber mining system with the leaving of supporting pillars and a pillar mining system with full backfill, which not only increase safety, but also increase the degree of mineral extraction. By comparing the obtained results, mining systems were determined that allow achieving the least deformations of the waterproof pillar and the greatest extraction.

Bespalov V. S. Safety assessment of undermining of waterproof pillar by the Krasniy-II layer in complex mining and geological conditions of the Verkhnekamsk salt deposit. MIAB. Mining Inf. Anal. Bull. 2026;(2-1):85-98. [In Russ]. DOI: 10.25018/0236_1493_2026_21_0_85.

V.S. Bespalov, Leading Engineer, PJSC «Uralkali», 618426, Berezniki, Russia; Lecturer, Perm National Research Polytechnic University, Berezniki Branch, 618404, Berezniki, Russia, e-mail: Bespalov.VS@yandex.ru, ORCID ID: 0009-0006-9129-0649.

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