Dynamic responses of an infinite beam on a layered water-saturated poroelastic foundation under moving loads

Based on the Biot's dynamic equation and the dynamic theory of elastic beam, the dynamic responses of an infinite beam resting on a layered water-saturated poroelastic foundation subjected to moving loads is investigated by the transmission and reflection matrices (TRM) method in this study. Applying the triple Fourier transformation, the general solutions for the water-saturated poroelastic foundation and the beam in the transformed domain are derived. Utilizing the continuity conditions between each layer and boundary condition at the surface of the half space, the equivalent stiffness of the layered water-saturated poroelastic foundation is obtained. Time-space domain solutions are obtained by means of IFFT arithmetic. The present methodology was validated by comparing present solutions with some known results. According to numerical results, it can be seen that the occurrence of a softer middle layer enhances the deformation of the beam.