Two and three-dimensional numerical analyses of geosynthetic-reinforced soil (GRS) piers

In this study, both two-dimensional (2D) and three-dimensional (3D) numerical analyses were carried out to evaluate the performance of geosynthetic-reinforced soil (GRS) piers. The numerical models were first calibrated and verified against test results available in the literature. A parametric study was then conducted under both 2D and 3D conditions to investigate the influences of reinforcement tensile stiffness, reinforcement vertical spacing, and a combination of reinforcement stiffness and spacing on the performance of GRS piers under vertical loading. Numerical results indicated that the effect of reinforcement spacing was more significant than that of reinforcement stiffness. The use of closely – spaced reinforcement layers resulted in higher global elastic modulus of the GRS pier, smaller lateral displacements of pier facing and volumetric change of the GRS pier, lower and more uniformly-distributed tension in the reinforcement, and larger normalized coefficients of lateral earth pressure. This study concluded that a 2D numerical model gave more conservative results than a 3D model.