Numerical evaluation of the effect of differential settlement on the performance of GRS-IBS

This paper presents the numerical results of the performance of the Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS) due to differential settlement underneath the reinforced soil foundation (RSF), underneath the reinforced zone including the RSF, and underneath the retained soil. The performance was evaluated in terms of reinforcement strain, lateral facing deformation, bump at the approach roadway-bridge slab intersection, and lateral facing pressure. Four different differential settlement values of 50, 100, 150, and 200 mm were selected for this study under three different service loading conditions corresponding to bridge spans of 24.4, 30.5, and 36.6 m. Simulations were conducted using the two-dimensional (2D) PLAXIS 2016 finite element (FE) program. The hardening soil model was used to simulate the backfill material behavior. The interface between the backfill material and the reinforcement was simulated using the Mohr-Coulomb model. The reinforcement and facing block were simulated using the linear elastic model. The results of FE analyses indicate that the differential settlement under the RSF has a high impact on both the strain distribution along the reinforcement and the lateral facing displacement.