A generalised soil–structure interaction model for circular plates on piles under vertical eccentric load

The growing demand for tall, slender structures in the energy and transportation sectors has driven the need for innovative foundation engineering solutions. Circular plates on annular pile groups are commonly adopted as a design choice to resist large, multi-component and cyclic loads, ensuring both the foundation’s safety and limiting deformations under service conditions. This work presents a generalised, physically based mathematical framework to assess both the safety and the displacement behaviour of circular plates on piles under combined axial and moment loads, including internal stress in the piles’ connecting plate. The model requires only a few parameters describing the axial constitutive behaviour of individual piles. Despite its simplifications, the method accounts for non-linearity, irreversibility, load-history dependence, pile-to-pile interaction, plate compliance and out-of-plane kinematics. It exhibits good performance when compared to centrifuge experimental data. An example applied to a wind farm highlights the advantages of the proposed framework in routine design of such foundations.