Centrifuge and numerical modelling of earthquake-induced soil liquefaction under free-field conditions and by considering soil-structure interaction

Modelling earthquake-induced soil liquefaction and assessing its consequences to overlying buildings are still delicate and challenging tasks in geotechnical earthquake engineering. Having been carried out within the European H2020 LIQUEFACT project, this paper focuses on the application of both physical and numerical modelling techniques. We present the complete passage starting from the preparation of the physical models to ending with the comparison of recorded (experimental) and simulated (numerical) results. We discuss in detailed manner the dynamic response of two systems with and without the presence of a structure lying at the top of a uniform, medium-dense, saturated Ticino sand, whose main properties (physical, mechanical, hydraulic, and state) are well known. Through a set of numerical analyses carried out under homogeneous conditions, we provide in this paper insights to throw light into the effect of structure on the system response. Salient conclusion of this work suggests that the presence of structure changes the kinematic response of the system through beneficial effect in terms of increased vertical effective stress and detrimental effect in terms of concentrated strain field present nearby the foundations. Unfortunate combination of those beneficial and detrimental effects results in stronger response in terms of acceleration and larger settlements with the presence of structure with respect to the free-field counterpart.