Investigation on grouting diffusion in inclined fracture with flowing water conditions

In this work, the grouting diffusion law of inclined fractures under flowing water conditions was studied, with the expression of slurry flow network in the infinite inclined plane based on potential flow superposition principle and the numerical model of the inclined fracture grouting process in flowing water established using COMSOL software. The influence of fracture dip angle and initial velocity of flowing water on the diffusion of the slurry was analyzed alongside the variation in pressure field, velocity field, and water flow during the diffusion of the slurry in the inclined fracture. The effectiveness of the numerical simulation method was verified by comparing the simulation results and experimental results. The results indicated that there is a limit value for the diffusion distance of slurry in the direction of smooth and inverse water, while increasing the inclination angle of the fracture contributes to the diffusion of the slurry against the water direction and width direction, which enhances the water plugging effect. The increase in the initial velocity of the water will increase the diffusion distance of the smooth water direction, will weaken the diffusion width of the slurry, and will lead to the grouting water plugging process requiring a longer time. During grouting, the flow velocity in the slurry diffusion width range will be significantly reduced, the water flow channel will be gradually narrowed, and the inlet flow decreased. The pressure field in the inclined direction of the fracture is essentially dominated by hydrostatic pressure.