Behaviour of anchored geosynthetic-reinforced slopes subjected to seepage in a geotechnical centrifuge

An anchored geosynthetic system (AGS) is an in situ reinforcing system that can be utilised to improve the stability of earth slopes. In this study, performance of AGS slopes under seepage conditions was investigated through a series of centrifuge model tests. These tests were conducted at an acceleration of 50g on silty sand slopes having 2V:1H and 1V:1H inclinations and reinforced with AGS in a large beam centrifuge located at the Indian Institute of Technology Bombay, India. Seepage was induced through a seepage simulator system to raise the water table within the reinforced slopes. The stability and seepage analysis was carried out for AGS slope models and the results were compared with those obtained from the centrifuge model tests. The results indicated that the location of the predicted failure surface in AGS slopes depended on the type of AGS load used for the analysis. The results of seepage analyses indicate that when the phreatic line was close to the physically observed phreatic line it nevertheless exits the face at higher elevation than physically observed in the centrifuge.