Soil-foundation compliance effect on seismic vulnerability assessment of RC structures

This paper presents an overview of soil-structure interaction effects on earthquake vulnerability assessment of reinforced concrete buildings. We examine (i) eighteen reinforced concrete building types, covering the structural typologies met in common engineering practice, (ii) seven soil profiles, representative of code-based soil classifications and (iii) three soil-foundation models, namely fixed-base, Beam-on-Nonlinear-Winkler elements and elastic springs. Eleven real earthquake recordings are used as input at bedrock level to obtain the corresponding free-field motions. Incremental Dynamic Analysis is applied to obtain a cloud of PGA - interstory drift pairs for all possible combinations. The corresponding fragility curves are derived and post-processed to estimate model-to-model differences within same structural typologies. The results are presented in heat map form, while an example in terms of loss curves is also given.