EVALUATION OF NATURAL-TECHNOGENIC STRESS FIELD DURING DEVELOPMENT OF DEEP HORIZONS OF AYKHAL DEPOSIT

Abstract

The Aykhal diamondiferous deposit is characterized by difficult geological and geomechanical mining conditions. In order to ensure safe conditions for the development of deep horizons of the deposit, there is a need for special additional research. A detailed analysis of geological and mining features of the field development was performed. Laboratory tests have allowed to specify physical and mechanical properties of rocks of a compound complex on the bottom horizons. As a result of the study of the tectonic structure and current geodynamics of the field area, the authors have obtained the data indicating the southeastern direction of the vector of maximum horizontal stresses in the Earth's upper crust, which is consistent with the results of precision GPS-observations. The results of the geo-acoustic study of the state of the rock mass in some areas of the mine field have allowed the parameters to be determined and the relatively low acoustic activity of the rock mass to be detected at the time of the measurements. The results of the performed researches have been used at justification of boundary conditions for modeling the rock mass and evaluation of change in the natural-technogenic stress field of the rock mass in deepening of mining operations. Development and implementation of the FEM models have allowed to trace the change in the naturaltechnogenic stress field as the reserves were successively extracted and the mined out area was filled with hardening mixtures followed by transition to the deeper horizons.