Behind a retaining wall, the mean effective stress mainly decreases during an excavation phase following an unloading stress path. The volumetric strains generated by purely elastic soils are systematically dilative which induces aberrant ground uplifts. The introduction of plasticity along with a nonlinear elastic domain turns out to be essential for a realistic prediction of ground movements. In this paper, a numerical analysis is carried out using a finite element code considering an advanced soil constitutive model called Generalized Hardening Soil which has been recently developed. This model contains the exact same set of features as the Hardening Soil Small Strain model but with the possibility to activate each of its plastic and nonlinear elastic mechanisms independently. The role of these mechanisms are investigated to assess their impact on the shape and the amplitude of the ground movements. Numerical results demonstrated that plasticity triggers the main contractive volumetric strains leading to settlements. Nevertheless it cannot fully compensate the elastic uplifts due to unloading. The insertion of strain dependent stiffness is essential as well as the stress dependency. A back analysis of the historical excavation of the Taipei National Enterprise Center permitted to validate these findings.
