Physical modelling of shaking table tests on dynamic soil-foundation interaction and numerical and analytical simulation

Earthquake geotechnical engineering has been recognised as an important branch of earthquake engineering. The analysis of soil-structure interaction may also be crucial when structural design problems are involved. Soil-structure interaction is a complex problem and needs to be analysed by physical and numerical modelling. Two physical models, consisting of a shallow foundation resting on a sand deposit, are tested on a shaking table to analyse soil-foundation interaction. The physical models are monitored, recording the time-histories of accelerations and displacements in the soil deposit and on the foundation. FEM codes are then employed to numerically model the resulting behaviour, using specific constitutive models and a new hand-made code based on the characteristic-line method. Simplified analytical approaches, still preferred in engineering, are discussed and developed. A comparison is made between the numerical and analytical results and they are also compared with the experimental results to validate the numerical modelling and analytical approaches and, in the new light of the Performance-Based-Design, evaluate their ability to predict foundation displacements (SLE) and bearing capacity (SLU). Interesting aspects about the seismic behaviour of the shallow foundation on the sand deposit are finally captured.