Abstract: Weathering is one of the most common diseases for earthen sites in northwest China. Surface sprinkling and hole grouting are two main methods to prevent weathering. Grouting experiments are performed on remolded soil samples with different dry densities to reveal the infiltration grouting diffusion laws of SH agent. An infiltration model of SH agent is established and the experimental phenomenon is reasonably explained. The volume of the soil reinforced by SH and the solid content of SH agent are obtained by calculation, and the solid content is proved to be sufficient to resist weathering for earthen sites. Through SEM images processed by Image J, pore distribution, pore fractal dimension and average Feret diameter under different dry densities are obtained. It is found that the permeability of soil decreases with the increase of dry density, because medium and large pores are compressed into micro and small pores. It is suggested that grouting experiment of SH agent should be applied to soil whose average Feret diameter is more than 4.98 ?m. Finally, by the method of multiple linear regression, it is found that grouting volume has the greatest effect on the infiltration radius, followed by average Feret diameter and aperture.

Key words: SH agent, infiltration radius, earthen sites, aperture