Development of Displacement-Softening Model for Interface Shear Behavior Between Geosynthetics

This paper presents two kinds of constitutive model applicable for geosynthetic interfaces, namely a combined model (MODEL 1) and DSC model (MODEL 2). In order to verify the performance of the two models, back­ predictions were carried out on smooth geomembrane (S-GM) and textured geomembrane (T-GM) interfaces with geotextile (GT), namely S-GM/GT and T-GM/GT interface using the parameters obtained from test results For the combined model (MODEL 1), the total stress field is divided into two regions, i.e. pre-peak and post-peak region, to take into account the displacement-softening effect on the interface shear behavior. The DSC model (MODEL 2) was also considered to model the interface shear behavior between geosynthetics. This model is comprised of two reference states, namely the relative intact (RI) and the fully adjusted (FA) state, and one function, namely the disturbance function. Though the comparisons between measured data and back-prediction results for MODEL 1 and MODEL 2 (DSC model) showed good agreements with each other, MODEL 1 has a critical limitation related to the boundary value problem as it is inconvenient to implement this model into FEM. Finally, DSC model (MODEL 2) was suggested as an appropriate model for simulating large-displacement shear behaviors with the characteristics of plasticity because the DSC model has been widely implemented in FEM process by many researchers.