Infiltration grouting mechanism of porous media considering diffusion paths of grout

The diffusion mode of grouting in porous media is mainly infiltration grouting, and the traditional infiltration grouting in porous media often neglects the diffusion paths in the process of slurry infiltration, resulting in a large deviation between the theoretical results and the actual ones. Based on the analysis of the diffusion paths in the slurry infiltration process of porous media, an infiltration grouting model for porous media considering slurry diffusion paths is established according to the equation for slurry diffusion. A set of infiltration grouting simulation experiment device for porous media is designed. The slurry-cement slurry is used to obtain the spatiotemporal variation of grouting pressure under different permeabilities of grouting media and grouting rates. The results show that the calculated values of slurry grouting model are 1.1 ~ 1.3 times the experimental ones, and the error between the calculated and experimental values is within the allowable range. The model can be used to describe the diffusion process of slurry infiltration. The calculated values of the infiltration grouting model for porous media, without considering the diffusion paths of slurry, are 1.8 ~ 3.2 times the experimental ones, and the slurry pressure of the grouting diffusion process is significantly overestimated. The research results have been applied in sand layer management of Qingdao metro. Therefore, the diffusion paths of slurry should be fully considered in the design of infiltration grouting in porous media.