A study on damage scenarios for residential buildings in Catania city

The main purpose of this study is to obtain the damage scenario for residen tial buildings in the occurrence of a destructive earthquake (M = 7+) in th e city area of Catania, Eastern Sicily, and to illustrate the comparative p erformance of two alternative methods used for this purpose. The methods ar e representative of two different approaches to estimating the seismic vuln erability of structures, i.e., an empirical approach based on statistical s core assignments (widely used in Italy and other countries) and a more rece nt, mechanical approach that uses displacement limit states associated with well-defined thresholds of structural damage. A special concern for seismi c vulnerability in Catania is caused by the fact that earthquake design nor ms were enforced in its municipal area only since 1981. We emphasise some t ypical problems encountered in earthquake scenario work, such as the diffic ulty of assembling a reliable building inventory, and the uncertainties inh erent in the vulnerability assessments through different probabilistic assu mptions. Different criteria for the representation of damage are applied an d discussed. It is shown that the main scenarios obtained by the two method s are in reasonable agreement, provided a suitable percentile level for dam age is chosen in the statistical score assignment approach.