Stabilized low-order finite-element formulation for static and dynamic simulation of saturated soils based on a hybrid integration scheme

This paper presents a stabilized linear finite-element formulation for three-dimensional (3D) elastoplastic static and dynamic coupled analyses of the soil skeleton and pore fluid. The proposed hybrid integration scheme can improve the speed and accuracy of the simulation while ensuring stability. The one-point reduced integration with hourglass stabilization and anti-locking strategy was used for the stress–strain calculation, while the full integration was adopted for analyzing other parts, such as the fluid phase. A robust pore-pressure stabilization method was derived to solve the oscillation problem for equal-order linear interpolation in the incompressible-undrained limit. In the field of large-scale 3D elastoplastic coupled solid–fluid simulations, academia has been committed to finding a method that considers the speed, stability, and accuracy of the simulation. The proposed finite-element formulation provides an effective solution for this purpose.