A Simplified Pseudo-Dynamic Model for Piles in Layered Soils Subjected to Seismic Loading

Abstract Pile-soil interaction under seismic loading is an important element to understand while designing piles in seismic regions. In this article, pile foundations in layered soils subjected to earthquake loading are considered. A versatile pseudo-dynamic p-y analysis method for modelling seismic soil-pile interaction was developed and evaluated against the results of existing dynamic centrifuge test data. The dynamic centrifuge experiments involved a single pile embedded in a layered soil profile composed of soft clay over dense sand and were carried out in two separate flights. The first flight was conducted without a pile-head mass to investigate kinematic interactions, followed by a second flight with a substantial head mass representative of a superstructure to generate combined inertial and kinematic interactions. One-dimensional ground response and dynamic p-y analyses carried out are described in detail. Following successful calibration of the numerical model against experimental results, a parametric study was carried out to examine the influence of pile diameter and earthquake intensity on seismic pile behaviour and to further assess the robustness of the method. The numerical predictions demonstrated good agreement with centrifuge test outcomes. Based on the analysis, non-dimensional bending moment relationships are proposed, offering a practical and efficient tool for preliminary seismic design of pile foundations across a range of soil profiles and seismic loading conditions.