Centrifuge modelling of the progressive failure of geosynthetic-reinforced embankments

Understanding the failure mechanism of geosynthetic-reinforced embankments on soft foundations is crucial for ensuring safety in design. This study aimed to investigate the failure mechanism and stability of embankments reinforced with varying layers and lengths of geosynthetic reinforcements utilising centrifuge testing and numerical modelling. The results show that a foundation under construction exhibits a progressive shear failure coupled with a tensile failure of the geosynthetic reinforcement. The plastic shear strain in the soft clay layer initiates at the centreline, shoulder and embankment toe and propagates both forward and backward until a critical slip surface develops. The tensile failure of the geosynthetic was observed at the embankment centre. Comparatively, implementing two shorter layers of geosynthetics proved more advantageous for overall stability than using a single layer with the entire length. By analysing the strain distribution in the foundation, the deformation modes of the embankment reinforced by different numbers of geosynthetic layers were clarified. It was found that increasing the number of geosynthetic layers extended the active shear zone in soft clay.