Experimental study on hybrid geosynthetic–reinforced slopes subjected to hydraulic actions

Given the increasing frequency of hydrological disasters and their impact on slope stability, this research focused on investigating the performance of hybrid geosynthetic–reinforced slopes subjected to floods and rainfall. Hydraulic scour apparatuses were developed to conduct scale model tests to investigate the change of some key evaluation indicators of slopes reinforced with different geosynthetics, such as pore water pressure (PWP) and volumetric water content (VWC). Results indicate that under rainfall conditions, in comparison to the unreinforced slope, the VWC, PWP, and earth pressure at slope toe, and crest settlement of the geotextile-geocell composite-reinforced slope decreased by 44.6%, 58.7%, 29.4%, and 44.7%, respectively. Under flood-scouring conditions, in comparison to unreinforced slopes, the PWP at slope toe, crest settlement, and cumulative soil loss for geotextile-geocell-reinforced slopes reduced by 27.7%, 41.8%, and 91.8%, respectively. The cumulative soil loss and settlement rate of geosynthetic-reinforced slopes subjected to the two hydraulic actions can be fitted using exponential function, and the correlation coefficient (R²) is 0.96. Under the two hydraulic actions, the geotextile-geocell composite achieves an optimal balance between PWP dissipation and residual earth pressure to improve the slope's anti-erosion performance through the geocomposite’s synergistic effect of “promoting drainage, resisting shear, and resisting deformation”.