Directional Confinement Effect of Geogrid on Deformation and Bearing Capacity of Reinforced Sand under Cyclic and Monotonic Loadings

Deformation behavior and bearing capacity of geogrid-reinforced sand were investigated through experimental study. Series of cyclic and monotonic loading tests were performed by using a large container, a rectangular footing and two geogrid types: triangular and biaxial. Footing orientation was considered as a parameter to examine the directional confinement effect of the geogrid. Test results showed that this effect was obvious on the development of permanent deformation and on the ultimate bearing capacity of reinforced sand. However, this influence became smaller on the ultimate bearing capacity if a stiffer geogrid was used for reinforcement. Significant reduction in permanent deformation and beneficial improvement in bearing capacity were observed in all geogrid-reinforced tests.