Mechanism and Symmetric Evolution of Mining-Induced Stress Field and Control of Roadway Deformation

Symmetry plays a fundamental role in the evolution of mining-induced stress fields and the deformation behavior of roadway surrounding rock. To improve control of roadway deformation under strong mining-induced disturbance, this study takes the 12 Upper 301 face at Buertai Coal Mine and investigates the deformation mechanism and corresponding control methods. Based on an analysis of in situ monitoring data, the key stratum responsible for energy accumulation in the overlying strata was identified. Based on the inherent symmetry of the longwall mining layout, a symmetric predictive model of overburden key-stratum abutment pressure is established, which reveals the spatially symmetric distribution characteristics of the mining-induced stress field. The accuracy of the theoretical model was further verified through a large-scale geomechanical similarity model test, which reproduced the fracture trajectory and stress evolution law of the overburden key strata. To mitigate strong mining pressure, a targeted hydraulic fracturing control technique aimed at specific overburden horizons was proposed and verified through field testing and application. Field monitoring results indicate that roof-to-floor convergence peaked at 235 mm, and rib convergence peaked at 115 mm. Compared with sections without hydraulic fracturing control, the surrounding rock deformation was reduced by 62.3% and 69.7%, respectively, demonstrating a significant pressure relief effect. This approach effectively ensured the roadway stability and enabled safe mining operations.