Predictive modeling on seismic performances of geosynthetic-reinforced soil walls

This paper presents the results of numerical parametric study of free-standing simple geosynthetic-reinforced soil (GRS) walls under real multidirectional ground motion shaking. The predictions were made using a validated finite element computer program. Design parameters, such as (1) wall height, (2) wall batter angle, (3) soil friction angle, (4) reinforcement spacing, and (5) reinforcement stiffness, were evaluated in the study. Prior to the parametric study, the extent of finite element model (FEM) boundary was verified in order to minimize the boundary effect. Results of parametric study were compared against the values determined using the Federal Highway Administration (FHWA) allowable stress design methodology. It was found that the FHWA methodology overestimates the reinforcement tensile load as compared to the FEM results. Multivariate regression equations were developed using FEM results for the various seismic performances based on multiple design parameters that are essential in the design of GRS walls. In particular, the prediction equations for wall facing horizontal displacement, wall crest settlement, and reinforcement tensile load are presented. The prediction equations can provide first-order estimates of the seismic performances of free-standing simple GRS walls.