Abstract: Rainfall-induced hydraulic scouring induced by rainfall is a significant factor contributing to slope instability and failure. To elucidate the impact mechanisms of various geosynthetic reinforcement methods on the hydraulic stability of slopes, laboratory slope hydraulic scour model tests were conducted. Comparative studies were performed on four slope configurations: unreinforced (J1), geotextile reinforced (J2), geotextile and geogrid composite reinforced (J3), and geotextile and geocell composite reinforced (J4). The results indicate that reinforcement materials improve slope hydraulic response characteristics, reduce overall moisture content, and enhance slope stability and drainage performance. Geosynthetic reinforcement reduces both the rate of accumulation and the stabilized value of pore water pressure, significantly diminishing slope earth pressure, settlement, and soil loss. Among the variants, J4 demonstrated the most pronounced effect, followed by J3, while J2 showed relatively weaker performance. Composite reinforcement system enhances slope resistance to erosion, with J4 delivering optimal protective effect in hydraulic erosion tests. The findings offer a reference for selecting geosynthetic reinforcement methods and for studying the mechanisms of slope resistance to hydraulic erosion.

Key words: hydraulic scouring, geosynthetics, reinforced slope, model test, slope failure characteristics