Effect of Particle Shape on Geogrid-Reinforced Granules

Abstract

Geogrids are polymeric products formed by joining intersecting ribs in a grid like pattern and are widely used to reinforce the granular soils used in road base and retaining walls. In geogrid-reinforced granular soils, the soil particles strike through the geogrid apertures and form a layer of reinforced granules which is commonly believed as the interlocking reinforcement mechanism of geogrids to improve the mechanical properties of the granular matrix. Previous experiments and numerical simulations are mostly focused on the stress-strain behaviors of the reinforced granules. Much study is needed to examine the reinforcement mechanism at the individual grain scale level, particularly the particle shape and rotation. In this paper, spherical class beads and joined-spherical glass beads reinforced with geogrids were tested under static triaxial compression tests to examine the effect of particle shape. The triaxial tests were performed at two confining pressures. 2D discrete element simulations of the triaxial tests were performed using PFC2D software to further examine individual particle movement during the shearing process. The results showed that angular particle shape can increase the geogrid reinforcement effect.