Behaviour of geosynthetic in anchored geosynthetic-reinforced slopes subjected to seepage

Abstract

The anchored geosynthetic system (AGS) is a technique to improve the stability of unstable or quasi-stable slopes. In this study, the behaviour of geosynthetic in slopes reinforced with AGS subjected to seepage is investigated. Centrifuge model tests were carried out at 50g centrifuge acceleration on silty sand slopes with an inclination of 63·4° (2V:1H) and reinforced with AGS. Seepage was generated by gradually raising the water table within the reinforced slope models. By means of a digital image analysis technique, the behaviour of the surface geosynthetic during the seepage was studied and the compressive stresses produced beneath the geosynthetic were determined. Limit equilibrium stability analyses were conducted with the application of AGS loads measured by digital image analyses. The results indicate that the maximum tension mobilised in the geosynthetic during seepage depends on the tension induced in the geosynthetic due to the anchorage prior to introducing seepage. Furthermore, including the compressive stresses produced by the tensioned geosynthetic in the analyses gives a more realistic value for the safety factors.