Failure mechanisms and characteristics of high-filled embankments with different types of basal reinforcement

The accurate evaluation of the failure mechanisms and characteristics of high-filled embankments reinforced by different basal reinforcements is essential for ensuring the safety of transportation infrastructure. This study conducted two centrifuge tests to investigate the failure mechanisms and characteristics of high-filled embankments reinforced by a geosynthetic and a concrete slab, respectively. The particle image velocimetry (PIV) technique was used to observe the initiation and progression mechanisms in the soft layer. The test results reveal that the geosynthetic-reinforced embankment exhibited a progressive shear failure mechanism and the soft layer exhibited strain-softening characteristics, while the embankment reinforced by the concrete slab exhibited instantaneous shear failure in a soft foundation. Based on numerical analysis, the relationship between the overall stability and the failure modes of the reinforced embankment system was revealed. The stiffness and layers of the basal reinforcements both had positive influence on the embankment stability when deep-seated rotational failure occurred. For embankment fills with low shear strength, employing a concrete slab as basal reinforcement led to general slope failure, and the global stability was determined by the shear strength of the embankment fill. The findings of this study may be useful for the design of transportation infrastructure.