FEM analysis of effect of reinforced layer numbers on bearing capacity and deformation of reinforced-sand retaining walls

In order to investigate the effect of reinforced layer numbers of reinforced-sand retaining walls, a series of results from plane strain laboratory model tests with different numbers of reinforced layers are simulated by a nonlinear FEM analysis incorporating an elasto-plastic constitutive model for sand. The constitutive model is developed to have a work-hardening and softening parameter based on the modified plastic strain energy concept, which can consider strength anisotropy, confining pressure dependency, strain localization (or shear banding) and the effects of stress history and stress path. The results indicate that the load-settlement relationships obtained from the FEM analysis are totally in good agreement with those from the physical experiment. It is found that the peak footing load of reinforced-sand retaining wall increases significantly with the increase of the reinforced layer numbers, although the total tensile stiffness (or total weight of material) of the reinforcements for each retaining wall model never changes. In addition, the results also indicate that the progressive failure of reinforced-sand retaining walls with a development of shear bands, the horizontal earth pressure on the back of facing and the tensile force in the reinforcement layers are reasonably simulated by the proposed FEM analysis, and the effect of the reinforced layer numbers on reinforced-sand retaining walls can be well understood.