Vertical vibration study of pile based on diffused fictitious soil pile model in inhomogeneous soil

Based on rule of stress diffusion, diffused fictitious soil pile model was constructed and the response of soil-pile under axial dynamic loading in inhomogeneous soil was investigated. Firstly, complex stiffness of different soil layers beside pile was gotten by using complex stiffness transfer model of radial multi-zone plane strain. And then combined with boundary condition, initial condition and continuity condition, the dynamical equations of diffused fictitious soil pile and real-body pile were solved from the bottom up. After that the analytical solutions of dynamic response at pile top in frequency domain and the relevant semi-analytical solution of dynamic response in time domain were gained. Finally, the influence analysis of angles of diffused fictitious soil pile, thickness of diffused soil layer, inhomogeneity of lateral soil of pile and length of pile were carried out. Based on diffused fictitious soil pile model, characteristics of the pile-soil coupling interaction in vertical vibration were gotten. The results can provide theoretical basis for dynamic pile design and testing.