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Abstract The pile dynamic response under high-strain condition(HSC) is the basis work of pile capacity prediction and pile driving analysis，which involves the soil strain history，elastoplastic characteristics，nonlinearity and slippage of the pile-soil interface. In order to simulate pile base soil under HSC，a discrete-element fictitious soil pile model was proposed in this paper，and a numerical differentiation solution was given. Firstly，the pile base soil was regarded as a fictitious soil pile with a certain diffusion angle，and the real pile and the fictitious soil pile were then discretized into a series of elements. The interactions between the pile elements and the soil elements were simulated by the linear viscoelastic model and the nonlinear spring-viscous damper-slippery parallel model，respectively，and the pile shaft resistance was calculated with a rheological model. The semi-sinusoidal impulse was applied for simulating the dynamic load acting at the pile top，and the velocity and displacement responses under different impulse widths and amplitudes were calculated combined with 3-dimensional finite element model(FEM) and the proposed model. Finally，the sensitivity analysis of related parameters was carried out. The results show that the fictitious soil pile model can consider the base soil vibration and the vertical propagation of the stress wave and is applicable for both low-strain and high-strain conditions. The proposed model can accurately predict the displacement and velocity response of the pile head under various impact conditions. The displacement amplitude increases approximately linearly with the increment of the impulse width and amplitude，whereas the velocity amplitude is not sensitive to the impulse width. The calculation results by FEM and the virtual pile model are consistent. Increasing the length of the fictitious soil pile and the soil nonlinearity degree or reducing the diffusion angle，the elastic modulus and the modulus ratio of the pile base soil would increase the peak velocity，the peak displacement and the residue displacement of the pile head. The fictitious soil pile model makes it possible to study the effect of soil distribution under the pile toe and has special value for simulating pile base soil and improving the dynamic calculation theory of pile foundation under HSC.
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