Seismic displacement based design of structures: relevance of soil structure interaction

In this paper a brief summary of the seismic design method known as “direct displacement – based design” (DDBD) is presented, with some discussion of the appropriate seismic design input to be used, on the applicability to retaining structures and on the relevance of including nonlinear soil-structure interaction in the DDBD and the tools to account for it, with reference to shallow foundations