Use of an advanced elasto-plastic model in the numerical analysis of a small-scale geosynthetic-reinforced wall from centrifuge tests

Over the last years, the increasing use of geosynthetics as reinforcing elements in soil structures has greatly encouraged sophisticated experimental work on laboratory models and advanced numerical analyses, in order to gain a better insight into the reinforcement mechanism as well as to validate or improve the existing design methods. A series of centrifuge tests on a geosynthetic-reinforced soil retaining structure with modular block facing has been recently carried out at the geotechnical laboratory of the Columbia University, with the aim of investigating the effect of reinforcement length and spacing on the wall response. This paper presents a finite element study aimed at simulating the experimental results obtained from the centrifuge physical model, whose behaviour involves a complex interaction between different structural components and backfill soil. A large part of the analyses has been carried out using an advanced, isotropic hardening elasto-plastic formulation, based on a multi-surface yield criterion in conjunction with the Mohr-Coulomb failure envelope. Such constitutive approach has been adopted to model the response of both backfill sand and interface elements, paying special attention to the calibration of the material parameters. A comparison between numerical and experimental results is proposed in terms of wall and backfill displacements as well as gravity field acceleration at failure.