Numerical simulation of deformation and failure behavior of geosynthetic reinforced soil bridge abutments

This paper presents a numerical investigation of the deformation and failure behavior of geosynthetic reinforced soil (GRS) bridge abutments. The backfill soil was characterized using a nonlinear elastoplastic constitutive model that incorporates a hyperbolic stress-strain relationship with strain-softening behavior and theMohr-Coulomb failure criterion. The geogrid reinforcement was characterized using a hyperbolic load-strain-time model. The abutments were numerically constructed in stages, including soil compaction effects, and then monotonically loaded in stages to failure. Simulation results indicate that a nonlinear reinforcement model is needed to characterize deformation behavior for high applied stress conditions. A parametric study was conducted to investigate the effects of reinforcement, backfill soil, and abutment geometry on abutment deformation and failure behavior. Results indicate that reinforcement vertical spacing, reinforcement stiffness, backfill soil friction angle, and lower GRS wall height are the most significant parameters. The shape of the failure surface is controlled primarily by abutment geometry and can be approximated as bilinear.