Analytical evaluation and experimental validation on dynamic rocking behavior for shallow foundation considering structural response

The challenge in the practical application of rocking foundations is the estimation of its performance, particularly the rotation angle, during a strong earthquake. In this study, the dynamic rocking behavior for a shallow foundation considering structural response was evaluated through two analytical approaches: the conventional soil-foundation-structure interaction (SFSI) governing equation of a single-degree-of-freedom (SDOF) structure on a rocking shallow foundation, and the Housner rocking model (i.e., a rocking rigid block on a rigid base). Both approaches were validated with dynamic centrifuge tests. The test models consisted of a soft soil deposit, a shallow rectangular foundation, and an SDOF structure dominated by a bending behavior. A total of 11 foundation-structure systems and six seismic waves, including recorded earthquake signals and sinusoidal waves, were utilized. The results showed that the conventional SFSI equation well predicted the maximum rotation during strong earthquakes. However, this method was less accurate regarding the rotational phase information and maximum rotation of the foundation during weak earthquakes. On the other hand, although the modified Housner’s rocking model required five parameters relevant to a soil-foundation-structure system, it overestimated the maximum rotation of the foundation when compared with the results from dynamic centrifuge tests.