An Analytical Model for Time-History Analysis of Earthquake-Induced Kinematic Demands on Piles in Layered Soils

This study presents an advanced analytical formulation for evaluating earthquake-induced kinematic demands on piles in layered soils. The pile is modelled as a Timoshenko beam on a two-parameter Winkler foundation, incorporating transverse and rotational soil–pile interactions within a time-history framework based on real and spectrally adjusted records. The formulation is validated against 3D finite element simulations, centrifuge tests, and simplified solutions. Results show high accuracy, with peak interface kinematic bending moments predicted within 5% of 3D FEM benchmarks. Kinematic demands are governed primarily by soil stratigraphy and peak ground displacement. Neglecting rotational interactions may produce discrepancies of up to 30%.