The article actualizes the problem of stable condition period of the interbed cap pillar by development of close-bedded sylvinite seams in outer areas of Verkhnekamskoye potash and magnesium salt deposit. As used here the focus is made on selection of the parameters for development of the minefield of Usolskiy potash plant (UKK). Estimation of tolerance time of the process interbed at different options of the development parameters supposed in UKK minefield has been performed by the procedure of «Galurgia» OJSC. Based on comparison of the geological features of productive seams bedding of UKK minefield with south-eastern site of Berezniki 2 «Uralkali» PJSC, taken as a sample, an issue has been raised on feasibility of consideration of the interbed cap pillar with thickness less than 2.5–3.0 m as a bearing element of the development system. Actual schedules of subsidence growth and rates in eastern sites 13, 15, 17 of the eastern panels (VP) have been produced. According to the schedules the actual subsidence growth rates meet the load degrees of common interchamber pillar, without impact of the interbed as a bearing element of the development system. Due to that three options of geomechanical solution have been proposed by selection of the parameters of the development system in UKK minefield, excluding or minimizing the impact of «weak» interbed on stability of geomechanical system.

Keywords

Geomechanical system, process interbed, water-insoluble residue, rock aggregate strength, load degree, development system parameters.