Research on grouting reinforcement technology of fault crossing roadway in fully mechanized mining face with large dip angle

To explore the problems of coal wall spalling and roof fall of a working face passing through a fault, the II 1044 working face with a large dip angle in the Taoyuan Coal Mine is taken as the engineering research background. FLAC3D is used to simulate the working face advancing towards the fault. The vertical stress distribution, plastic zone evolution, and fault slip displacement characteristics of the stope are studied when the working face is advanced to different positions, and safety measures are formulated accordingly. The research shows that the vertical stress and the stress concentration area in the lower part of the working face with a large dip angle are larger than those in the upper part of the working face. As the working face advances towards the fault, the slip amount of the silt rock is the largest, and the slip amount of the immediate roof is the smallest. When the working face is 40 ∼ 50 m away from the fault, the influence of mining on the fault slip characteristics changes from weak to strong. Therefore, it is decided to apply grouting 40 m from the fault in the working face, reducing the probability of coal wall spalling. Related monitoring data show that the support pressure of the working face is stable between 23 MPa and 35 MPa after grouting, which is far less than the support pressure without grouting at approximately 45 MPa. Therefore, the pressure grouting method is effective in this working face.