Procedures and experiences in the post-earthquake usability evaluation of ordinary buildings

One of the most critical issues in a post-earthquake emergency is assessing the usability of buildings in order to recommence daily life in the stricken area while ensuring the safety of people returning to their houses. Generally, this is done by means of surveys based on usability forms filled out by expert technicians. Different countries adopt different forms, all that assess usability in terms of building damage. The Italian approach takes into account, in addition to the building's damage, the vulnerability of the building. In this study, the data collected through the widespread survey performed in the aftermath of the L'Aquila (Italy) 2009 earthquake was analysed, showing that some buildings were judged not usable despite having no or very little damage. The role of other causes, including vulnerability, in the determination of unusability are discussed. Finally, a practical case faced by the authors during the usability survey in Emilia (Italy) after the 2012 seismic sequence highlights the role of vulnerability in the usability outcome.