DEM Investigation of Geosynthetic Nonlinear Tensile Behavior on Bearing Capacity and Deformation in GRS Abutments

Abstract

This study develops a Discrete Element Method (DEM) framework to investigate the influence of geosynthetic tensile nonlinearity on the deformation and load-bearing behavior of GRS abutments. The nonlinear tensile response of polyolefin reinforcements is characterized using a hyperbolic load-strain model and implemented at the particle scale through a strain-dependent variable stiffness contact formulation based on the parallel bond model. The DEM framework is calibrated and validated against laboratory test results. Simulation results indicate that reinforcement tensile nonlinearity has a limited influence on footing settlement and deformation under serviceability conditions (ε v = 1%), where reinforcement strains remain small. In contrast, at the strength limit (ε v = 5%), neglecting stiffness degradation leads to a significant overestimation of bearing capacity and underestimation of deformation. Parametric analyses further show that reinforcement stiffness, vertical spacing, and backfill friction angle strongly govern settlement development and ultimate capacity, whereas footing setback distance and length have comparatively minor effects. These findings highlight the necessity of incorporating nonlinear tensile behavior of reinforcement for reliable prediction of deformation and bearing performance of GRS abutments under high loading conditions.