A hierarchical roof control and pressure relief method for Gob-side Entry Retaining with Compound Roof

Abstract Gob-side entry retaining is effective for preventing gas accumulation, extracting pressure relief gas, and removing gas from the goaf. This study, based on the No. 312 mining area of Longtan coal mine, aims to clarify roof cutting and pressure relief foundations, calculate key parameters, and propose a roof control method. Using field detection, theoretical analysis, and numerical simulation, the dynamic response of roof drilling and fracture mechanics of hard rock strata were examined. Results indicate that the hard rock stratum dictates the pressure relief mode and difficulty. The failure zone distribution in the hard rock stratum is directly influenced by roof cutting borehole density. Consequently, pressure relief methods, key parameters, and roof control measures under different roof conditions were identified. Engineering applications and monitoring show that the hierarchical roof control and pressure relief method ensures rock stability and significantly enhances pressure relief and roadway retention efficiency.