An analytical solution for seismic response of pipe piles under vertical ground motion considering water-pile-soil interaction

An analytical model is developed for an end-bearing pipe pile in a water-pipe pile-soil system subjected to vertical ground motion, where the kinematic response of the pipe pile is considered solely in terms of its vertical displacement. The system's response to ground motion is decomposed into two components: the free field and the scattered field. By incorporating the water-soil interaction in both the inner and outer domains, the response expressions for water and soil are derived. Subsequently, the displacement continuity and stress equilibrium within the inner and outer domains of the pipe pile, as well as at its various cross-sections, are thoroughly considered to derive an analytical solution for the overall system response. Finally, the sensitivity of the vertical dynamic response of the water-pipe pile-soil system to each parameter is analyzed.