Multi-parametric seismic vulnerability assessment of free-standing columns

Harmonic and seismic excitation was used for studying the structural behaviour of different free-standing column typologies using 2D discrete element modelling in UDEC 5.0 [1]. Based on an extensive archaeological survey, a set of realistic parameters was de-fined for the seismic vulnerability assessment of these elements, namely the soil characteris-tics, slenderness, height and number of drums. It was shown the influence of slenderness, size effect and number of drums. The more slen-der elements were found to be the less stable, for the same slenderness the taller column is characterised by higher stability. However, since for harmonic analyses the relation between the results of the different elements tested under different frequencies usually do not vary ac-cording to a robust law, it was not possible to give quantified results for the effect of each pa-rameter based only on the harmonic excitation results. This quantification of the results became possible using dynamic analyses with earthquake time-histories instead of harmonic excitation. Based on the seismic analyses results, fragility curves were created for all exam-ined soil-column configurations for quantifying the influence of all investigated parameters. This research is being carried out as part of the Italian project “PROVACI” [2] that deals with seismic protection and valorisation of cultural heritage.