Numerical Analysis of Reinforced Soil Walls with Finite Element Method

Abstract

The technique of reinforced soil has been widely used in construction of retaining walls and levee foundations. Nowadays geosynthetic reinforced soil walls are one of the important options in the design of retaining walls due to their superiority than other reinforcements. Traditionally, the design of geosynthetic reinforced soil walls is performed using the simplified classical analysis or empirical methods. Unfortunately, the applications of these methods render various degrees of approximations in determination of major designing factors. In this research, the behavior of geosynthetic reinforced soil walls is studied by the numerical method (FEM) with PLAXIS 2-D software. The numerical model simulates the panel with beam elements, the reinforced layers with geogrid elements and the soil-structure contact area with interface elements. Furthermore, the Mohr-Coulomb plastic model is used for the soil. The wall construction is modeled with staged construction. Then, numerical models are calibrated by using instrumented model results or experimental model and the ability of PLAXIS software in prediction of wall displacement, facing deformation and tension of reinforcement layers is assessed. Finally, one of the models is selected and the parametric study is performed. The effect of factors such as: property of soil, type of mesh and stiffness, length, distance and number of reinforcements on reinforced soil wall behavior will be investigated. The effect of changes in length of reinforcements on the model output results compared to the model are calibrated. In that case, the length of reinforcements than the calibrated models have changed, the maximum displacement of the wall is a big change than calibrated model. According to the results of numerical analysis, increasing the length of reinforcements, the effect of small on the maximum deformation of the facing has a total height of the wall. When the length of reinforcements have reduced or increased, the tension in reinforcements than the calibrated model respectively increased or decreased.