The Influence of the Deformation History on the Location of Rock Destruction

Abstract

The Verkhnekamskoe deposit of potassium-magnesium salts was used as an example of modeling the destruction of rock mass taking into account the history of its deformation (a retrospective analysis). The method of the geomechanical estimation of changes in the stress-strain state of the salt mass over time was considered using the elastoplastic approach for the conditions of the plane strain state. The influence of the deformation history of the rock mass on safe mining operations was estimated both for the current and long-term predictions with displacements progressing over time, taking into account the Mohr-Coulomb criterion relations and ultimate tensile stresses. We analyzed the prospects for the formation of sub-vertical jointing zones in the undermined mass, which play the key role in the formation of the undermined stratum of water conducting channels along the section. It is shown that without the retrospective analysis, the geomechanical estimation of the rock strata destruction is not always adequate for a current situation of deformation and can lead to overestimated values of the stability of the rock mass, which is unacceptable for safe mining.