Centrifuge modeling of the geogrid-reinforced slope subjected to differential settlement

A series of centrifuge model tests of geogrid-reinforced slopes with superstructure was conducted under differential settlement condition. The influence of reinforcement placement on the deformation and failure behavior of the slope and superstructure is investigated by considering different numbers of geogrid layers. The response of the slope and superstructure is analyzed based on a full-field displacement measurement via image analysis. The differential settlement induces distinguishable superstructure movement and slope deformation above the subsidence zone. The slope displacement, close to the vertical direction, appears only in a limited zone. An integrated analysis scheme of deformation and failure processes is adopted to reveal the failure mechanism of both the unreinforced and reinforced slopes: a certain level of deformation localization induced by differential settlement results in the local failure, and adversely, the local failure aggravates the deformation localization near it. The geogrid reinforcement mechanism is further clarified as the reduction on the deformation localization of the slope due to geogrid placement. The geogrid reinforcement effect can be comprehensively described with two respects: hooping effect and shielding effect, which illustrates the influence sphere and degree of geogrid reinforcement on restraining the slope deformation. The geogrid reinforcement is proven effective to improve the safety of the slope and superstructure.