An explicit finite element method for Biot dynamic formulation in fluid-saturated porous media and its application to a rigid foundation

An explicit finite element method for Biot dynamic formulation in fluid-saturated porous media is proposed. The decoupling-technique is used in the explicit finite element method. It does not need to assemble a global stiffness matrix and solve a set of linear equations in each time step, so the computational effort and memory requirement can be reduced considerably by using this method. The method is applied to analyze the dynamic response of a massless rigid foundation in a fluid-saturated porous medium. The computational results are compared with those of the elastic solution in a single-phase medium for the same problem, and it shows that if the frequency of the incident movement on rigid foundation is high (close 10 Hz), the dynamic response of the rigid foundation in fluid-saturated porous media is larger than that in single-phase media.