At present, the development of minerals is carried out and designed at great depths. Practice shows that at depths of about 800 m the stability of mine workings significantly deteriorates. To predict their stability, it is necessary to comprehensively investigate the physical and mechanical properties of rocks, especially rheological properties, such as stress relaxation.

Physical and mechanical properties of salt rocks were investigated in laboratory and underground conditions with respect to the problems of rock mechanics – calculation of rational parameters of room-and-pillar mining and identification of patterns of rock pressure manifestations. These tasks are of great importance in mining the Starobinsk potash deposit, represented by several potash seams, occurring at a depth of 420–640 m from the surface. At the deposit, two potash seams are mined with thicknesses of 1.8–4.0 m and 4.5–7.0 m, occurring respectively at depths of 420 and 580 m.