Time-dependent behavior of viscosity of quick setting slurry and double liquid grouting mode lead to spatial uneven distribution of viscosity in diffusion region. The influence of spatial uneven distribution of viscosity should be considered in permeation grouting diffusion model of quick setting slurry. By regarding quick setting slurry as a Bingham liquid of time-dependent behaviour

an even capillary group model is used to describe porous flow process. A theoretical model of one-dimensional permeation grouting is developed under constant grouting rate. A visual permeation grouting simulation test system is designed to obtain the permeation rates of different media and the relationship between grouting pressure and grouting time for cement-sodium silicate (C-S) slurry. Results show that: when the spatial uneven distribution of viscosity is considered

the calculated value of grouting pressure is 1.2-1.4 times the test value and the calculated value of grouting distance is 0.9-1.1 times the test value. The theoretical and experimental results are in good agreement. The proposed model can well describe the process of one-dimensional permeation grouting of quick setting slurry. When the spatial uneven distribution of viscosity is not considered

the calculated value of grouting pressure is 3.5-4.1 times the test value and the calculated value of grouting distance is 0.5-0.7 times the test value. So the grouting pressure is overestimated significantly and the grouting distance is underestimated. The spatial uneven distribution of viscosity should be considered carefully in grouting design.