Abstract: In the process of grout penetration in sandy soil, the soil skeleton particles filtrate cement particle leading to an anisotropic diffusion, referred to as filtration effect. In this paper, Kozeny-Carman model is adopted to analyze the influence of filtration on soil porosity, permeability coefficient and slurry flow velocity. A constant pressure device is employed to investigate the grouting quantity variation of sand samples with different grading associated with different grouting parameters. Then, a quantitative relationship is obtained using multiple regression techniques. Test results show that filtration effect remarkably influences plugging behavior of cement grout and cement particle mass fraction is the main controlling factor of the grouting distance. According to Darcy’s law and regression relationship, theoretical values of grouting distance are determined with considering the filtration effect and ignoring the filtration effect respectively. Comparisons to the tested value indicate that omission of filtration effect lead to a considerable deviation of the theoretical value. Results can be used to instruct grouting design and offer references to similar projects.

Key words: sandy soil medium, filtration effect, constant pressure penetrating grouting, diffusion law, multiple regression analysis