Study on the Stability and Deformation of the Roadway Subjected to High In-Situ Stresses

To investigate the deformation and failure mechanism of the roadway under high in situ stresses at the 958 section in 2# mine in Jin Chuan, China, field and numerical investigations were conducted. Field investigations on the loosen ring of the roadway show that great roadway deformations and failure in surrounding rocks may result from poorly functioned bolts. Based on the old supporting system, a new supporting system characterized by the installation of steel pipe beams and the elongated bolts was proposed and applied in field. Field data indicate that the roof sag, rib convergence and floor heave significantly decrease. The numerical study illustrates that the properly functioned bolts and steel pipe beams are responsible for the decrease of roadway deformation. To further control the roadway deformation, two additional supporting systems were proposed and simulated. The increase of the bolt density contributes to reinforcement of the surrounding rocks and the floor heave in the first support system is under controlled. In the second support system, the installation of bolt on floor successfully restrains floor heaves accordingly.