A New Spatial Coupling Model for Foundation Uplift and Its Application

In earthquake engineering, soil–foundation–structure interaction (SFSI) is a crucial phenomenon that must be investigated. This paper presents a new spatial coupling model capable of computing SFSI while considering the foundation uplift phenomenon. The proposed model can calculate the variations in the horizontal, rocking, and torsional impedance of the foundation during the occurrence of foundation uplift. To validate the proposed model, the changes in the impedances of the foundation, considering foundation uplift, are calculated using both the proposed model and the thin‐layered method. The results demonstrate that the proposed model for the impedance of the foundation during the uplift procedure achieves sufficient accuracy. Additionally, the dynamic response of a tower considering the foundation uplift phenomenon under earthquake excitation is analyzed. A comparative analysis reveals a significant difference in structural responses between the proposed model and the sway‐rocking model under the influence of foundation uplift.