Dynamic soil-structure interaction analysis by experimental and numerical modelling

The paper deals with a coupled dynamic soil-foundation-superstructure interaction (DSSI), which was investigated by means of a 1-g shaking table test, consisting of a 5.0x1.0x0.9 m sand deposit and a 1.30x0.95x1.30 m steel frame. The system was subjected to sine-dwell horizontal acceleration time-histories and monitored by numerous accelerometers and displacement transducers. The shaking table test was simulated by numerical FEM analyses, using a linear visco-elastic (LE) constitutive model for the soil, which is still widely used in professional practice, as well as a sophisticated visco-elasto-plastic constitutive model with isotropic and kinematic hardening (NL) that is definitely more appropriate for dynamic analyses. The dynamic response of the system has been analysed in the time and frequency domains. The main goals of the paper are: i) to investigate the effects of soil non-linearity and DSSI in terms of accelerations and displacements in soils and on structures that could be useful for practical engineering purposes ii) to highlight some crucial aspects of numerical modelling when reproducing shaking table tests on DSSI. This paper is part of a long-term research activity consisting of numerous tests and related numerical simulations, firstly on dynamic soil-foundation interaction (DSFI) and secondly on DSSI.