Study on Surrounding Rock Disaster Mechanism and Stability Control of Soft Rock Roadway Under Deep High Stress

Large deformation and difficult support are common in soft-rock roadways under deep high-stress conditions. The 1232(3) gob-side roadway of Dingji Mine was taken as the engineering background. A combined approach was used. It included theoretical analysis, numerical simulation, field measurements, and underground tests. The catastrophe mechanisms of surrounding rock and the corresponding stability control technologies were investigated for high-stress soft-rock roadways. The results showed a strong Rp–Rw effect. When the variation coefficient of the maximum horizontal principal stress satisfied Rp > 0.8, the influence on the variation coefficient of roof buckling deflection (Rw) became pronounced. Under this condition, roof deformation increased markedly. As roadway drivage changed from solid-coal-side driving to gob-side driving, the surrounding-rock stress became progressively asymmetric. The peak stress on the coal-pillar side decreased from 25.3 MPa to 21.5 MPa. The plastic zone expanded continuously. Its dominant development also shifted from the roof and floor toward the two ribs. After entering the gob-side condition, plastic-zone development on the coal-pillar side generally exceeded 2.5 m. The original support bolts could no longer remain effective. Different stress states and failure characteristics were observed on the solid-coal side and the gob side. Based on these differences, an asymmetric coupled support and surrounding-rock control system was established. The system integrated “time effectiveness + regional zoning + targeted reinforcement.” A field trial was conducted in the 1232(3) haulage roadway. Surrounding-rock deformation was effectively controlled, and favorable engineering performance was achieved.