Abstract: In order to study the diffusion mechanism of slurry in soil-rock mixture and its influencing factors, a reusable indoor grouting model test system was developed with the Chongqing soil-rock mixture as the research object. Experimental study of grouting model of soil-rock mixture under conditions of different stone contents, porosities, slurry viscosities and grouting pressures was carried out. The results show that slurry diffuses mainly in the soil-rock mixture by means of osmotic and splitting. When the stone content increases, the main diffusion mode of the slurry shifted from splitting to osmotic. When the medium contains stone, the splitting diffusion is equivalent to the osmotic. On the basis of experiments, the grouting diffusion radius prediction model of soil-rock mixture is established based on the theory of support vector machine. Based on the calculation results of the model, the order of influencing factors for the infiltration diffusion radius and the splitting radius are obtained respectively. Which are: stone content>slurry viscosity>porosity> grouting pressure; stone content> grouting pressure>slurry viscosity>porosity. The stone content has the greatest influence on the diffusion form, and it domains the diffusion radius value. It is suggested that the engineering should design the grouting parameters according to the stone content.

Key words: soil-rock mixture, stone content, slurry diffusion mechanism, prediction model, influencing factors