Study on Surrounding Rock Control Technology of Composite Soft Rock Roadway in Deep Inclined Strata

To address the challenge of controlling the deformation of surrounding rock in deep high-stress interlayer tunnels, this study focuses on the engineering background of severe deformation of surrounding rock in a water drainage tunnel of a mine in the 22nd mining area, which traverses multiple layers of inclined soft rock. By employing theoretical analysis and numerical simulations, the research investigates the mechanisms of deformation and failure, as well as the support technologies for interlayer tunnels. The findings include: Under different geological conditions, the vertical stress distribution of roadway surrounding rock shows obvious asymmetric characteristics, and the stress concentration area of left side is more significant than that of right side. Under different geological conditions, the vertical stress distribution of roadway surrounding rock shows obvious asymmetric characteristics, and the stress concentration area of left side is more significant than that of right side. The difference of different rock strata leads to different stress concentration of roadway surrounding rock in different parts. Mudstone and sandy mudstone are weak, which easily leads to stress concentration and surrounding rock damage, and the deformation of roof, floor and shoulder of roadway is more serious. The volume of plastic zone of surrounding rock is significantly affected by the physical and mechanical properties of rock strata. In particular, the existence of soft rock strata will make the surrounding rock of the roadway more prone to plastic flow damage, resulting in the instability of the surrounding rock, and the expansion range of the plastic zone of the roadway is significantly larger. Based on this, a combined support scheme for cross-layer roadway is proposed, which effectively controls the deformation and failure of roadway and improves the overall stability of cross-layer roadway.