A COMPARATIVE NUMERICAL STUDY OF A GEOSYNTHETIC-REINFORCED SOIL WALL USING THREE DIFFERENT CONSTITUTIVE SOIL MODELS

In this paper, three different soil constitutive models for granular soils were implemented in the numerical simulation of a full-scale reinforced soil segmental wall in order to predict the wall response during construction. The soil constitutive models in the order of complexity are: linear elastic-perfectly plastic Mohr-Coulomb, Duncan-Chang hyperbolic, and a nonlinear elastic-plastic hardening model. The latter, which can be regarded as a modified version of the Mohr-Coulomb model, captures the nonlinear stress-dependent soil response. The nonlinear model can consider soil dilative behavior. In this regard, it keeps the simplicity in the formulation together with the accuracy in the prediction of soil response. By comparing the results, in general, there is good and acceptable accordance between numerical simulations and field measurements. It is seen that using a simple soil model can acceptably predict the performance of reinforced walls. However, the disadvantage relates to poorness in the prediction of wall facing displacement, which is sensitive to proper consideration of deformation parameters in a soil model. The accuracy of the prediction can be augmented by adopting reasonable functions for elastic (stiffness) and plastic (dilatancy) parameters with respect to the stress condition within the soil backfill.