Study on Hydraulic Characteristics of Ryegrass-Polypropylene Fiber Reinforced Soil Slopes Under Rainfall

Polypropylene fiber,as a synthetic material,possesses numerous unique advantages.Ryegrass is highly effective in improving the erosion resistance of slope soil.Their synergistic effect provides excellent cost-effectiveness and environmental benefits.The erosion resistance and hydro-mechanical properties of ryegrass-polypropylene fiber reinforced slopes under different polypropylene fiber contents,slope gradients,and rainfall intensities were investigated via rainfall simulation tests.The experimental results indicate that under rainfall conditions,the ryegrass-polypropylene fiber composite significantly influenced the reinforced soil slope’s performance.The variations in volumetric moisture content and pore water pressure of reinforced soil slopes follow the sequence: slope toe>mid-slope>slope crest.The volumetric moisture content and pore water pressure of polypropylene fiber-reinforced slopes first decreased and then increased with increasing fiber content.The optimal reinforcement effect was achieved at a polypropylene fiber content of 0.5%,at which the volumetric moisture content and pore water pressure of the slope reached their minimum values.The capacity of ryegrass to reduce volumetric moisture content and pore water pressure of fiber-reinforced soil slopes increases with rising slope gradients and decreases with higher rainfall intensities.Compared to polypropylene fiber reinforced soil slopes and bare soil slopes,slopes with a ryegrass-polypropylene fiber-soil particle structure exhibit superior erosion resistance and soil conservation capabilities,providing soil stabilization,runoff interception,and infiltration promotion during rainfall.