Equivalent finite element method for long-term settlement of subgrade induced by traffic load

Traffic load may produce a significant settlement of subgrade on saturated soft soils. This work aims to develop an equivalent finite element method to calculate the long-term settlement of subgrade. The pseudo-static method is used to calculate the dynamic stress ratio. An explicit stress-strain model is developed from the experimental data of axial plastic strain and accumulated pore pressure and then integrated into the initial-strain-based equivalent FEM. The equivalent FEM is established using the user-defined subroutine offered by the commercial FEM software. As an illustration, the equivalent FEM is used to compute the settlement of a typical cross-section of a road. It is found that the maximum strains are distributed near the side of road surface, and the maximum settlement is located in the central area of road surface.