Speaker Prof. Jaime Santos Instituto Superior Técnico (IST) Technical University of Lisbon Portugal Abstract Soil-structure interaction problems under either static or dynamic loading have been the major problem to dominate in modelling the behavior of building and general civil engineering structures. Movements of structures or internal movements of ground are still difficult to evaluate mostly by the lack of information about the stress-strain behavior of soil under small strains. The deformation properties at these small strains can be linked to the elastic properties, although the stress-strain behavior could be highly non-linear. This has led to the development of design methods that take this into account, such that stiffness non-linearity is now routinely incorporated into many standard computer codes. These achievements ...