Single-ring infiltrometers were used to explore the infiltration behavior of gravel-rich soil. Spikes of infiltration rates were registered in the infiltration histogram, supporting the slit-snap-off and pore-snap-off conceptual model proposed by Tuller et al. The results of the in situ infiltration experiments also indicate saturated hydraulic conductivity is linearly related to volumetric
gravel content when gravel content exceeds 30%. To facilitate the estimation of saturated hydraulic conductivity on gravelly soil, a multiple regression equation considering volumetric gravel content,total porosity, and effective particle size D10. was obtained.
Key Words : Infiltration behavior, saturated hydraulic conductivity, gravel volumetric content, total porosity, effective particle size.