Bearing capacity, shear band evolution, and deformation characteristics of slopes reinforced by root-inspired anchors using transparent soil model testing

Root-inspired anchorage systems in the field of bio-inspired geotechnics are renowned for the elevated pullout capacity of traditional geotechnical anchorage systems by simulating the morphology and architecture of plant root systems. However, limited study has explored their practical applications, particularly in improving slope stability. To fill this gap, this study explores the reinforcement effect of root-inspired anchors on slope stabilization using transparent soil modeling and 3D printed anchors, and examines the impact of anchor branching patterns (i.e., branching numbers, branching angle and branching nodes) on slope bearing capacity, shear band evolution and temporal and spatial variation of slope deformation. The results show that peak slope bearing capacity increases with branching numbers and branching angle, correlating with the envelope area of the curved shear band. Upper anchors result in step-like deflection of shear band near the trailing edge, while lower anchors convert the upward concave shear band into an upward convex one, thus increasing the slope bearing capacity. Slope deformation is minimized with intermediate branching parameters, i.e., branching number of 4 and branching angle of 45°. The anchor reinforcement mechanisms, i.e., anchor rod shear resistance, interface friction, anchor pullout capacity and plate tightening effects are comprehensively discussed, and the compromising modeling-induced installation effects is one of the contributors. These findings shed light on the failure process of root-inspired anchors reinforced slopes and provide a preliminary reference for potential applications, especially the trade-off between anchor branching, slope deformation and slope stability.