Seismic fragility of some Italian RC building types accounting for seismically induced displacements

In order to extend the results of a previous project (Seismic Risk Maps, MARS-1) carried out in the period 2019-2021, mainly devoted to assessing the seismic risk of residential and school buildings, a new research project (named MARS-2) was funded by the Department of Civil Protection for the period 2022-2024. Beyond extending the study to other assets at risk (e.g. churches, hospitals and bridges), MARS-2 focuses also on multi-hazard risk scenarios including seismically induced secondary hazards, particularly landslides, liquefaction, and tsunami. Special attention is paid to slow-moving landslides and the effects of differential soil displacements they produce at the base of buildings located on the crest of slopes. In the paper, the procedure for assessing the impact of seismically induced displacements is described in order to derive fragility curves (FCs) combining both ground shaking (GS) and ground failure (GF) effects. Combined FCs are derived for one building type representative of the existing reinforced concrete building stock in Italy and compared to the corresponding ones obtained in the 2019-2021 MARS project without ground failure for the damage levels proposed in the EMS-98 scale. Finally, results are analysed to highlight the influence of the cumulative damage due to ground shaking on seismic fragility.