Deformation behaviour of geotextile reinforced sand slopes

Abstract

Internal mechanisms of failure of geotextile reinforced slopes are particularly due to: (i) rupture of reinforcement layers and (ii) pull-out of geotextile layers. This paper concerns about the study of deformation behaviour of geotextile reinforced slopes resting on a firm foundation layer. Centrifuge tests were performed in a 4.5 m radius large beam centrifuge facility available at Indian Institute of Technology Bombay. In order to simulate the failure to reinforcement layers, ratio of length of the reinforcement to height of the slope is maintained as 0.85 and the slope is constructed with a scaled-down geotextile material by using a wrap-around technique to represent flexible facing. Three centrifuge model tests were carried out on geotextile reinforced sand slopes by varying the type of reinforcement and vertical spacing while, slope inclination (2V:1H) and placement void ratio were maintained as constant. Reinforced slope models were subjected to varied g-level (in steps of 5 g from 10 g onwards) up to a maximum set g-level of 75 g or collapse, whichever occurs earlier. Image analysis technique was adopted to arrive at strain distribution along reinforcement layers. Results of the centrifuge tests indicate that the failure of geotextile reinforced slopes initiate approximately at its mid height. Further, this paper addresses the stability analysis and deformation behaviour and usefulness of a centrifuge modelling technique in modelling the deformation behaviour of geotextile reinforced slopes.