Fragility Curves for Assessing the Seismic Vulnerability of Multi-Drum Ancient Columns

The paper deals with an assessment of the seismic fragility of multi-drum ancient columns in the probabilistic assessment framework of incremental dynamic analysis (IDA). The dynamic response of multi-drum ancient is governed by the motion of stone-drums which can rock and slide individually or in group, individuating different possible collapse mechanisms, which are also depending on ground motion intensity. In this research, two different in geometry columns i.e. different height and number of drums analysed. The columns were modelled using the UDEC software based on the discrete element method (DEM). IDA was carried out for 10 ground motion records with and without considering the vertical component of earthquake excitation, in order to assess also its influence on the resulting fragility. Results are provided in terms of fragility curves and allow evaluating the influence of the geometrical assembly of the columns and vertical component of the ground motions.