Sull’uso di un modello costitutivo avanzato nello studio del comportamento di un muro in terra rinforzata.

This paper presents a numerical study of the behaviour of a geosynthetic-reinforced soil retaining structure, using a finite element approach in conjunction with an advanced, isotropic hardening elasto-plastic formulation, based on a multi-surface yield criterion and the Mohr-Coulomb failure envelope. The study is based on the experimental data collected in the context of a centrifuge testing programme performed on a small-scale geosynthetic-reinforced soil retaining structure, with the aim of investigating the influence of a number of design parameters, such as length and vertical spacing of the reinforcement layers, on the wall response. Since the numerical response of such system is strongly influenced by the assumption on the interface element behaviour, special attention has been paid to the proper description of the complex interaction between different structural components and backfill soil. The numerical predictions have generally confirmed the trend behaviour observed in the experimental tests, i.e. that the reinforcement length plays a leading role in the overall response of the wall model, whereas a minor effect of the reinforcement spacing has been detected. The study has solely focused on the analysis of the so called global failure, which is strongly affected by the failure surface size and thus by the reinforcement length. Further numerical analyses are required in order to take into suitable consideration other mechanisms, such as breakage of the reinforcement or pullout failure.