ADAPTING A GENERALIZED PLASTICITY MODEL TO REPRODUCE THE STRESS-STRAIN RESPONSE OF SILTY SOILS FORMING THE VENICE LAGOON BASIN

A Generalized Plasticity model, originally developed for the analysis of sandy soil behaviour, is modified in order to properly simulate the stress-strain response of a wide class of non-active natural soils, forming the upper profile of the Venice Lagoon basin. The main modification consists in introducing a state-dependent dilatancy, which allows proper modelling of granular soils over a wide range of pressures and densities, fulfilling at the same time basic premises of critical state soil mechanics. Moreover, according to recent developments on the isotropic compression of granular soils, few adjustments are introduced in the plastic modulus expression. The approach is validated by comparing the model predictions with experimental data obtained from drained triaxial compression tests on natural and reconstituted samples of soils having different fine contents.