Coupled dynamic model for pile-soil-periodic-viaduct under moving loading

When a periodic viaduct is subjected to moving loadings, the vibrations of the superstructure, pile foundation and soil will be coupled. To investigate the dynamic response of the periodic viaduct considering the pile-soil-structure interaction, a boundary element model for the pile-soil system is established to determine the compliances of the pile foundation. By using the governing equations for piers and beams, the corresponding transfer matrices are derived. According to the joint conditions at the beam-beam-pier (BBP) junction, the transfer matrix at the junction is obtained. To improve the proposed model, the Timoshenko beam theory is used to describe the ?exural vibrations of the piers and beams. By means of the Fourier and the sequence Fourier transforms, the frequency domain response of the periodic viaduct under a single loading is reduced to an integral of the frequency-wavenumber domain response function over the representative span of the viaduct. Employing the transfer matrices of the piers, beams and BBP junctions as well as the compliances of the pile foundation, the response function for the coupled vibration of the viaduct is obtained. The numerical results show that there are obvious differences between the dynamic responses of the rigidly-supported and pile-supported viaducts.