Abstract: To explore the characteristics of the seepage grouting process of fractured rock, this study designed a set of rock fracture grouting experimental systems, including slurry supply, data monitoring, and grouting simulation sub-systems. Through the grouting experiment of single fracture sandstone under different grouting pressures (0.3, 0.4, 0.5 MPa), the variation of pipeline flow pressure, slurry flow rate, and slurry pressure were analyzed, and the influence of slurry parameters on flow characteristics was discussed by numerical simulation. The experimental results show that the pipeline flow pressure, slurry flow rate, and slurry pressure show a three-stage characteristic of rising-stabilizing-falling. In the stable stage, the three variables positively correlate with the grouting pressure, but the sensitivity to the change in grouting pressure is different. With the increase of grouting pressure, the slurry pressure increases, while the response of slurry flow to the change of grouting pressure gradually decreases (when the grouting pressure increases from 0.3 MPa to 0.5 MPa, the slurry flow increases by 15.3% and 8.1% respectively). When the grouting pressure reaches 0.3 MPa, the flow pressure in the pipeline remains unchanged. The numerical simulation results show that the slurry flow is related to its diffusion form in the fracture. When the diffusion is semi-circular, the slurry velocity decreases, and the flow rate increases. The slurry velocity increases when the diffusion form changes from semicircle to convex. When the diffusion form changes from convex to uniform diffusion, the parameters tend to be stable. The slurry flow rate and flow velocity are inversely proportional to the plastic viscosity of the slurry. The increase of the plastic viscosity enhances the effect, while the slurry yield stress has little effect on the flow rate and flow velocity.

Key words: penetrative fracture, grouting tests, slurry diffusion, diffusion law, slurry parameters