Abstract: With horizontal cracks as the premise, conventional models of penetrative grouting diffusion do not reflect the impact of the occurrence of rock mass cracks on the grouting diffusion mechanism. In view of this, a theoretical diffusion model of grouting in dip cracks at constant grouting rate was established in consideration of the uneven spatial distribution of viscosity based on the theory of fluid mechanics and equivalent hydraulic aperture of rough walled cracks. Quick setting double slurry (cement-sodium silicate slurry), commonly used in engineering geological hazard treatment, was regarded as Bingham liquid with time-dependent behavior of viscosity in static water environment and was chosen as the grouting material. The dead-weight of grouting slurry itself was taken into consideration, Furthermore, the space-time distribution equation of viscosity and pressure in the diffusion region of slurry was derived. And the relations of grouting pressure versus grouting time and grouting diffusion distance were quantitatively determined. Finally, the slurry diffusion characteristics in the presence of different occurrence of cracks at constant grouting rate was studied by means of laboratory tests and finite element analysis procedures. Comparison between numerical simulation results and theoretical calculations verified the validity and rationality of the theoretical model. The results may be constructive to the determination of grouting parameters of quick setting slurry in practical engineering.

Key words: quick setting slurry, dip crack, grouting, diffusion model, time-dependent behavior of viscosity, grouting parameters