Rock mass management to ensure safe deposit development based on comprehensive research within the framework of the geomechanical model development

Abstract

Purpose. To create and study a three-dimensional geomechanical model in order to determine the parameters of the open-pit walls and benches, ensuring safe and economically feasible mining, as well as predicting unstable zones within the open pit. Methods. A comprehensive methodological approach is used, including a systematic analysis of scientific, normative and methodological literature; analyzing the results of previously performed studies on the object; engineering-geological surveys in the near-edge rock mass of the Kurzhunkul’ deposit; laboratory testing of rock strength properties; determining the rock mass rating according to the MRMR classification; kinematic analysis of bench faces; calculating the stability of the Kurzhunkul’ deposit final boundary using the limit equilibrium method; numerical modeling of the rock mass stress-strain state at the Kurzhunkul’ deposit using the finite element method. Findings. The paper represents the results of data collection and analysis for the development of a geomechanical model of an operating iron-ore open pit in the Republic of Kazakhstan. Comprehensive geomechanical studies to substantiate the optimal parameters of the Kurzhunkul’ deposit walls and benches on the limiting contour, as well as calculations to determine the degree of the open-pit walls and benches stability have been performed. Based on the results of studying the geological-structural configuration of the deposit, as well the mathematical modeling data of stability and acting stresses, subsequently entered into a unified digital database, weakened zones have been identified. Originality. For the first time, the geomechanical model has been created for the conditions of the Kurzhunkul’ deposit, which makes it possible to combine in one database all the parameters that affect the safety of mining operations. The model takes into account structural disturbances of the rock mass that have an adverse impact on stability. Practical implications. The developed model gives a visual representation of the rock mass state at various sites of the deposit, simplifies the selection of design sections for stability calculations, facilitates the choice of optimal technical solutions and analysis, especially for complex geological structures with multiple geotechnical or geological units with different texturing and inclination.