Assessment of a vulnerability model against post-earthquake damage data: The case study of the historic city centre of L'Aquila in Italy

The quantitative measure of seismic vulnerability is a necessary requirement for prevention and for an optimal emergency management. Before L'Aquila's earthquake in 2009, the National Civil Protection, in collaboration with the University of L'Aquila, developed a model (Beolchini, "Definition of an indicator of urban vulnerability" (2003)) to evaluate the criticality seismic of urban centers by using a multidisciplinary approach. The study has led to the definition of an urban vulnerability index, that allows to identify the most critical urban centers and the problematic elements, in order to establish a hierarchy for preventative measures and for an efficient emergency management (Calvi et al. "Development of seismic vulnerability assessment methodologies over the past 30 years" (2006). One of the features of this evaluation is that it allows a simultaneous analysis of the multiple factors involved in risk assessment (Ferlito and Pizza "Modello di vulnerabilità di un centro urbano. Metodologia per la valutazione speditiva della vulnerabilità della viabilità d'emergenza" (2011); Ferlito et al. "Danger treblement de terre et mesure du risque à L'Aquila" (2010)). After the seismic event occurred, same tests have been done to verify the validity of the model on the part of buildings, by comparing the criticality evaluated and damage suffered by the buildings, taking into account the local effects resulting from operations of microzonation. The seismic vulnerability index is calculated as the weighted sum of same parameters, that represent a building feature which can affect the structural response under earthquake ground motion. Therefore, the influence of each parameter and their respective weights on the model have been analyzed. Sensitivity analyzes were performed to understand the model parameters that most affect structural vulnerability. Furthermore the aim of this work is to provide a correlation between the indicator of criticality proposed here and the possible damage to the buildings resulting from an earthquake, As for the test performed, the methodology has a good level of confidence in the modelling of the vulnerability of the buildings so it can be successfully used for seismic risk assessment, necessary for seismic safety and emergency management. © 2013 WIT Press