A COMPARATIVE NUMERICAL STUDY OF A GEOSYNTHETICREINFORCED 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.