Failure characteristics and engineering stability control of roadway surrounding rock based on deviatoric stress field

Aiming at the failure mechanism and stability control of roadway surrounding rock,based on rock mechanics and other related theories,the analytical solution of the deviatoric stress field of surrounding rock is deduced,the distri- bution of surrounding rock under different conditions is analyzed,and the constitutive equation of the deviatoric stress field and the plastic zone distribution is established. It shows that the radius of plastic zone is related to the angle of polar coordinates and the size of deviatoric stress,and can be an irregular distribution. Combined with engineering practice,numerical simulation and analysis are used to simulate and analyze the evolution process of deviatoric stress and plastic zone in the surrounding rock under different stress states when the vertical stress is larger than the horizon- tal stress (λ = 0. 4) and the horizontal stress is greater than the vertical stress (λ = 1. 6). According to the field investigation and the evolution characteristics of the plastic zone,the authors put forward that at different lateral pressure co- efficients the roadway will form a typical pattern symmetric instable and a typical angular symmetric instability mode, also,the authors analyze the misunderstanding area with these two failure modes of roadway support,and the corre- sponding control principle and key technologies. Combined with the engineering practice of the Mukong coal mine and Gaokeng Coal Mine,“Bolt+Cable” support is applied to the main support named “high strength rigid truss” integrated support technology to help improve the stability of the sizes. In addition,the “key parts grouting” is used to enable the inside and outside coupling of “ Bolt+U-steel+Cable” comprehensive treatment program. The application shows that the two are able to control alternative symmetric instable roadway and angular symmetric instability roadway.