Research on Boundary Position Optimization for Very Close Vertical Distance Cross-mining Face and Surrounding Rock Stability of Floor Roadway

The vertical distance between the cross-mining working face and the 630 track transportation of the bottom plate is 6 m in a mine in Shanxi Province. In order to improve the coal recovery rate and ensure the long-term stability of the floor roadway,the elastic-plastic theory and numerical simulation software are used to establish the plane mechanics model and the numerical model under the advanced and lateral support pressure, the stress distribution characteristics and deformation laws of the floor roadway in the advanced high stress zone and the low stress zone after mining are obtained. The results show that the optimal horizontal distance from the boundary of cross-mining face to floor roadway is 15 m. According to the stress distribution characteristics and deformation laws of the floor roadway under the influence of dynamic pressure, the combined support technology of “partial grouting with high-strength anchor rod cable” was proposed in a targeted manner. The monitoring results show that the reinforcement effect is obvious and the normal use of the main roadway is guaranteed.