Incorporation of the soil-structure interaction into performance-based design

A performance-based design is aimed at controlling the structural damage based on precise estimations of proper response parameters. This is possible if more accurate analyses are carried out, including all potential important factors involved in the structural behaviour, as is the case of soil-structure interaction. This paper presents a simplified procedure for practical damage analysis of structures elastically supported, with potential application to performance-based design. The damage model proposed here is based on maximum displacement and dissipated energy under monotonic loading, with the effects of cyclic behaviour and load reversals being estimated by using a modified Park-Ang index. Analyses are made for a single elastoplastic structure with embedded foundation in a stratum over rigid bedrock. This is done by using an analogy with an equivalent fixed-base oscillator defined by the coupled period and damping of the system and its global ductility. Selected numerical results are presented in terms of dimensionless parameters, the significance of soil-structure interaction in the structural performance is elucidated and the adequacy of the approach presented is examined.