First-aid and provisional devices in historical structures with collapse risk after seismic shock

Realization of first-aid devices for the safety of heavily damaged structures of the Cultural Heritage assets is one of the main problems in the post-earthquake emergency phase. However, the adopted solutions, characterized by the utmost urgency, often appear uneven, ineffective and expensive. Six years after the earthquake in Emilia Romagna Region, which damaged numerous historical buildings, above all churches, it seems worthwhile to reflect on the management of the post-earthquake emergency and reconstruction interventions. As a matter of fact, in 2012, many Public Institutions were unprepared to deal with such an event: the lack of an appropriate knowledge about how to intervene in such conditions has led to solutions that are unnecessarily expensive, technically ineffective and, sometimes, even harmful for the building itself. Frequently, the strengthening devices had to be entirely redesigned during the subsequent phase of definitive intervention, entailing additional costs for the removal of those realized in the emergency phase. The cases in which the provisional devices have been designed in preparation for the final strengthening, sometimes even becoming definitive themselves, are rare. Therefore, this experience has raised some reflections concerning the functionality of the temporary safety measures. It has been noticed that an appropriate design of the provisional devices is fundamental in order to avoid interventions that could compromise the value of the architectural asset, to allow the knowledge of the structure for designing the definitive strengthening and to consider the permanent implications of such safety measures. This note presents some case-studies related to strengthening actions following the 2012 earthquake in Emilia, aiming to identify possible solutions for implementing the first-aid interventions in an integrated way with the subsequent strengthening phase in order to significantly reduce economic, material and time costs.