Numerical analysis of non-linear soil-structure interaction

The present paper deals with a parametric study of soil-foundation-frame interaction in pseudo-static conditions by means of a new finite element code, named SOFIA. The analysis is performed considering strip foundations resting on linear and non-linear soil elements. The seismic actions are simulated by means of a pseudo-static approach. Even if the code is used for soil-foundation-frame systems in plane-strain conditions, the 3-D effect is taken into account through an approximate procedure. In particular, in this paper the effects due to the soil-structure relative stiffness and the number of storeys in the superstructure are taken into account. The results, reported in a-dimensional form to be as general as possible, show some interesting differences between the static and pseudo-static behaviour of the soil-structure system and the importance of considering the soil nonlinearity.