Ricerc@Sapienza

This paper presents a displacement-based design procedure to rationally account for
the effects of soil-foundation structure interaction in the seismic design of shallow
foundations. The non-linear deformations at the soil-foundation interface, such as
foundation uplift, soil yield and soil-foundation shear deformation can dramatically alter
the dynamic response of a building. The lack of consideration of the modifying factors
of SFSI and an absence of procedures for controlling foundation and soil behaviour
under seismic loads has resulted in inadequate designs for buildings sited on soft soil.
A soil-foundation macro-element model was used to calibrate expressions to quantify
the non-linear foundation rotational stiffness as well as the effects of foundation energy
dissipation and soil-foundation shear deformation on the response of the soil-structure
system. A series of concrete wall buildings were designed with the proposed design
procedure and numerically assessed to validate the suitability of the design procedure.
The simple hand calculation procedure presented here quantifies the modifying factors
of SFSI in an intuitive and direct manner to allow engineers to design buildingfoundation
systems with a clear understanding of their expected performance.