Centrifuge model tests of geogrid-reinforced slope supporting a high embankment

Abstract

This study evaluated the deformation behaviour, vertical stress, strain, and failure mode of a 14 m-high (H) geogrid-reinforced slope supporting an 8 m-high embankment using centrifuge models. Tests were conducted at an acceleration of up to 40g. Additional tests were conducted to investigate the effects of layer spacing (0.5 to 1.0 m at prototype scale) and slope inclination (45° to 90°) on the performance of the reinforced slopes. The maximum strain (∼0.04%) occurred in the reinforcement layer nearest to the crest of the slope. Potential slip surfaces were identified from peak strains in the reinforcement layers. The vertical stress was redistributed owing to the tensile behaviour of the geogrid, and vertical stress within the soil slope was transferred to the area near the face of the slope (0.26–0.77H from the face). As the layer spacing increased (from 0.5 to 1.0 m), the potential slip surface moved away from the slope face with increasing deformation, which reduced the overall stability of the reinforced slope. The model with a vertical slope generated the largest reinforcement strain (∼0.2%), vertical settlement, and surface bulging compared with the model with a mild slope.