Dynamic response characteristics of floating pipe piles considering the three-dimensional soil deformations

The dynamic response of floating pipe piles under axial dynamic loads considering the soil three-dimensional wave effects is studied in this paper based on the Tajimi’s continuous medium model. The soil layer is treated as Tajimi-type viscoelastic continuum, and the vertical and radial displacements governing equations of outer and inner soil are established respectively. The governing equations is decoupled by introduced potential functions, and the expressions for the displacement of the outer and inner soil is obtained by means of the method of separation of variables, then the expressions for the vertical dynamic soil resistances is derived. The pipe pile and its underlying soil column is regarded as one-dimension rods and the governing equations describing vertical displacements of pipe pile and soil column is established. The analytical expression for the vertical displacement of pipe pile is finally obtained by considering pile-soil interaction and combining boundary conditions. Based on the solution, the differences in dynamic response between floating pipe piles considering three-dimensional wave effects of soil and those ignoring the radial displacement of soil are discussed.