Semi-analytical and semi-numerical method for plane strain consolidation of double-layer foundation considering stress paths

In this work, a simplified solution method is present for the elasto-plastic consolidation of a double-layer foundation under different stress paths. A double-yield surface model is introduced as the constitutive model framework for saturated clay and sand. Using a Gauss kernel function, a partial derivative coefficient sequences is obtained. Then, the model is applied to Biot's consolidation equations and to establish incremental governing partial differential equations for the plane strain consolidation problem. By simplifying the continuity equation as a Poisson equation, the fundamental solutions are derived for double-layer foundation model. Based on it, a semi-analytical and semi-numerical method is presented which is implemented in our finite element program. Comparisons with different mesh show that the stability of the numerical method is good. Moreover, the consolidation of semi-infinite double-layer foundation models is analysed under two stress paths (conventional loading path under the condition of isotropic consolidation CTC and conventional loading path under the condition of anisotropic consolidation K-0+CTC). It is shown that the model can reflect the influence of stress path, loading distribution width and some other factors on the deformation of the soil skeleton and pore water pressure. This simplified solution appears to be more convenient than the traditional coupling stiffness matrix method.