Sustainable approaches to the assessment and mitigation of seismic risk and of the effects of earthquake induced damages to historic urban centers

Fundamental lessons have been learned from recent destructive earthquakes in Italy (Friuli Venezia-Giulia 1976, Irpinia-Basilicata 1980, Umbria-Marche 1997, Abruzzo 2009, Emilia-Lombardia-Veneto 2012) on crucial issues, from the point of view of the conservation of CH, as the management of post-earthquake recovery operations and the adoption of preventive seismic risk mitigation plans of historic centers. It became in fact more and more clear from the technical and scientific points of view that both the stabilization of even the most severely damaged buildings and the preventive improvement of the structural response to seismic actions of historical constructions have to be attained “minimizing” interventions that must be in any case specifically tailored for each single case, carefully considering its historical and artistic values, and designed on the basis of equilibrium considerations of every single portion/component of the structure and of “technical/economical optimization procedures” in the selection and use of the available, whatever traditional or innovative, technologies. Substantial achievements were clearly attained in this context in terms of sustainability, being the abovementioned approaches clearly in perfect agreement with the principles of conservation of CH and at the same time with the necessity of as much as possible reducing the costs of interventions, given the more and more strict financial/economic constraints. Impressive were the effects on the adoption of such approaches in adapting to CH contexts the methodologies traditionally use during post-earthquake recovery operations, a field where the Fire Brigades and the National Civil Protection Agency, the bodies in charge for such activities, were more and more cooperating with the Ministry of CH. The ministry of CH for its part, more and more aware that there cannot be good conservation practices without a direct involvement of the Ministry itself in structural safety issues, took important internal organization initiatives in the above context, particularly to make more efficient the activity of its own central and local offices in safeguarding not only the architectural heritage but also the mobile artistic artifacts in the post-earthquake recovery operations and to promote effective, being “sustainable”, seismic risk mitigation measures of historic centers.