5. Conclusions
This paper presents a macro-element formulation for predictive assessment of the effects of SFSI. The model captures the major nonlinear aspects of SFSI through two interacting constitutive models. The plasticity model captures the effects of soil yielding, while the uplift model captures the geometric non-linearities during footing uplift. The macro-element was implemented in the time history analysis software Ruaumoko3D and numerical simulations were compared to two sets of seismic centrifuge tests. In the first experiment, a pier structure was shaken to levels close to toppling using both recorded and pulse type ground motions. The second experiment was a one bay, single storey frame structure with a non-linear superstructure and isolated footings, exposed to recorded ground motions at varying levels of intensity. In both cases the macro-element model provided suitable simulation of the transient behaviour of the foundation and superstructure. The model also provided reasonable estimates of settlement and in some cases the residual foundation rotation was also modelled accurately. The macro-element provides an intuitive and numerical efficient tool for simulating complex non-linear soil-foundation-structure interaction. The validation and continued development of soil-foundation macro-elements is a promising path forward to allow SFSI to be widely considered and understood in structural engineering. The development and implementation of this macro-element was a key step towards the development of integrated displacement-based design and assessment procedure for building-foundation systems [24,25].
