Information support for geomechanical calculations of stability of the undermined rock mass with a complex tectonic structure

Abstract

Using the example of the Tyubegatan potash deposit (Uzbekistan), a complex of geophysical and geomechanical safety assurance for mining operations in conditions of the complex tectonic structure of the undermined rock mass is considered. Geophysical research included ground-based seismic surveys using a profile system in combination with «light» standard electro- and gravimetric techniques. Based on the results of these works, a physical and geological model of the deposit areas was built with the weakened zones and faults localization. As part of the meaningful interpretation, the physical and geological model was transformed into a geomechanical calculation scheme, which reflected the main mining-geological and mining-technical condition of development and was based on a model of elastoplastic deformation of salt rocks. The geomechanical model was calibrated from radar interferometric surveys. The time factor was taken into account in accordance with the developed modification of the well-known method of variable deformation modules. The formation of plasticity zones in physical terms was identified with the formation of fracturing areas in the water protection layer, which determine the danger of violating its continuity. Numerical implementation of the geomechanical model using the finite element method made it possible to substantiate the optimal parameters of the chamber development system, ensuring the safety of the water protection layer, including fault zones.