Abstract
Comprehensive consideration of the geomechanical and structural characteristics of the rock mass is a prerequisite for ensuring the safety and efficiency of underground mining operations. The key parameters that must be incorporated into computational models include the physical, mechanical and strength properties of rocks, their degree of fracturing, as well as the initial and mining-induced stress state of the rock mass. This study investigates geomechanical criteria for determining support parameters of development workings under conditions of plastic deformation. The methodological framework is based on a combination of theoretical analysis, finite element numerical modeling using the RS2 software package (Rocscience), and generalization of experimental data on the properties of host rocks. This approach enabled a detailed analysis of the stress-strain state of the rock mass at various stages of mining operations, including the roadway junction where a new roadway is driven from an existing excavation and its subsequent development. The modeling results established the spatial boundaries of deformation zones: the depth of developed inelastic deformation reaches 0.6–0.7 m from the excavation boundary, while the elastoplastic deformation zone extends to 1.8–1.9 m. Stress analysis showed that in the abutment pressure zone ahead of the excavation face, stresses reach values of 20.48 MPa, which is about 25% higher than the in-situ stress level at a depth of 600 m. Analysis of the Factor of Safety (FoS) revealed local zones with FoS < 1 in the junction zone, indicating the need for reinforcement of the support system. The results provide a scientifically substantiated basis for predicting the geomechanical state of the rock mass and for selecting rational support parameters, thereby improving excavation stability, reducing maintenance requirements, and enhancing industrial safety in underground coal mining.