Numerical parametric study to evaluate the performance of a Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) under service loading

This paper presents the evaluation of the performance of the Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) in terms of lateral facing deformation, strain distribution along geosynthetics, and the location of potential failure zone (locus of maximum strain) subjected to service loading. Simulations were conducted using two-dimensional (2D) PLAXIS 2016 Finite Element (FE) program. The hardening soil model proposed by Schanz et al. (1999) was used to simulate the behavior of the backfill material; the interface between the backfill materials and the reinforcement was simulated using the Mohr-Coulomb frictional model, and the reinforcement and facing block were simulated using the linear elastic model. The numerical model was first verified using results of a field case study conducted at the GRS-IBS of Maree Michel Bridge, Louisiana. A parametric study was then carried out to investigate the effects of abutment height, span length, reinforcement spacing, and reinforcement stiffness on the performance of the GRS-IBS. The results of the FE analyses indicate that the abutment height and span length have significant impact on the maximum strain distribution along the geosynthetic, and the lateral facing displacement. It was noted that the reinforcement stiffness has a significant impact on the GRS-IBS behavior up to a certain point, beyond which the effect tends to decrease contradictory to the reinforcement spacing that has a consistent relationship between the GRS-IBS behavior and the reinforcement spacing. The results also indicate that the reinforcement spacing has greater influence on the lateral facing displacement than the reinforcement stiffness for the same reinforcement strength to spacing ratio (T-f/S-v), mainly due to the composite behavior resulting from closely reinforced soil.