Substantiation and selection of parameters for supporting mine workings at deep levels

Purpose.The research aims to conduct a comprehensive study on substantiation and selection of optimal parameters for supporting mine workings at deep levels by analyzing the stress-strain state (SSS) of the rock mass, modeling geomechanical processes and developing effective strengthening technologies in difficult geological conditions. Methods. The research includes modeling of the stress-strain state of the rock mass using ANSYS, Phase2 and Prorock software packages. To assess and predict the stress-strain state of the mass in the area of stope blocks, a series of numerical experiments have been conducted to analyze the near-contour rock mass stability. The physical-mechanical characteristics of ores and host rocks are used as input data for modeling. Findings. The mass SSS analysis has confirmed that increasing the number of cable bolts up to four provides mine wor-king stability, but is accompanied by intensive fracture formation beyond the contour, as well as convergence up to 14 cm, which requires the use of reinforcing mesh and reinforcing frame in two layers. The mining system elements have been found to provide the necessary safety factor for end ore drawing (ks ≥ 3.0) and slicing mining with hardening backfill (ks ≥ 5.0). Originality. The parameters for supporting mine workings have been substantiated, which ensures safe mining of deep levels. It has been revealed that when backfilling, the height of the caving zone is 125 m and the fracture zone is 60 m. For mining systems with caving, these figures reach 280 and 470 m, respectively. Practical implications. The technology has been developed for supporting capital mine workings with the use of reinforced combined support and roof bolts. The results obtained contribute to the improvement of reliability and efficiency of mining operations by providing accurate prediction of rock behavior under conditions of changing stresses and reduction of their strength characteristics.