A finite–discrete element framework for the 3D modeling of geogrid–soil interaction under pullout loading conditions

The behavior of a geogrid–soil system under pullout mode is known to depend on the properties of the geogrid material, the backfill soil and the interface condition. Modeling the geogrid–soil interaction taking into account the true geogrid geometry is a challenging numerical problem that requires the consideration of the discontinuous nature of the soil and the different modes of resistance that contribute to the pullout capacity of the geogrid layer. In this study, a coupled finite–discrete framework has been developed to investigate the behavior of a biaxial geogrid sheet embedded in granular material and subjected to pullout loading. Validation is performed by comparing experimental data and numerically calculated results using the proposed model. The detailed behavior of the geogrid and the surrounding soil is then investigated. The numerical results indicated the suitability of the coupled model to solve this class of problems.