Dynamic response solutions of unsaturated soil foundation using soil-water characteristic curve considering deformation effects

To investigate the dynamic response of unsaturated soils under moving loads, a new soil-water characteristic curve (SWCC) model is established considering the deformation caused by applied load based on the traditional V-G SWCC model. Using this modified SWCC model, a dynamic governing equation for unsaturated soils, which fully describes the water-force coupling effects of unsaturated soils under dynamic loading, is derived. The governing equation is solved using the 2.5-dimensional finite element method (2.5D FEM). The obtained solutions are compared with the analytical ones for single-phase medium, double-phase saturated medium and three-phase unsaturated medium, respectively, which all confirm the accuracy of the proposed solution method. The computational time analysis for different medium models demonstrate that the 2.5D FEM is an advantageous algorithm for solving the dynamic problems of porous media. The numerical analysis reveals that using the traditional SWCC without considering the deformation will underestimate the vibration intensity of unsaturated foundations.