Research on Ground Directional Grouting Reinforcement Technology and Coupling Control of Fault Fracture Zone Through Rock Roadway

The fault fracture zone has the characteristics of low strength and poor water resistance. These factors often lead to stress concentration and significant deformation during roadway excavation. In order to improve the anti-deformation ability and strength of the surrounding rock and reduce the support pressure, taking the roadway passing through the F2 fault in the Wugou coal mine as an example, the evolution characteristics of the surrounding rock of the roadway passing through the fault were studied using FLAC3D numerical simulation software, and the stress evolution law and failure characteristics of the surrounding rock in three stages of the roadway driving through the fault fracture zone were analyzed. The slurry diffusion characteristics under different grouting hole layouts were studied using COMSOL software, and the effectiveness of ground directional grouting (combined directional drilling technology with ground grouting technology) reinforcement technology was explored via similar simulation experiments. After the pre-grouting reinforcement of the surrounding rock by the ground directional hole in the field, the fault fracture zone was successfully excavated. The key technical system of the shield roadway passing through the fault based on the directional drilling and ground grouting technology was summarized and put forward. The three-hole drilling and the circumferential four-hole drilling layouts were used to realize the grouting in the fault fracture zone. Engineering practice shows that ground directional grouting has significant advantages and improves the mechanical properties of the broken weak surrounding rock. The deformation of the roadway roof is 128 mm, and the deformation of the two sides is controlled within 100 mm. This method greatly improves the stability of the roadway and has been verified by the field results.