Emergency actions and investigations on cultural heritage after the L’Aquila earthquake: the case of the Spanish Fortress

The earthquake occurred on the 6th of April 2009 in the Abruzzo Region of Italy, seriously hit the Cultural Heritage (C.H.) patrimony with major destructive effects on L’Aquila, a city of 70,000 inhabitants with the size and the historical and strategic importance of the Region capital. The emergency activities to protect the C.H. have been developed on two parallel levels: (1) survey and assessment of damages, (2) implementation of temporary safety measures. The organization of the emergency actions was managed by a centralized structure, the so called Function 15 “Protection of Cultural Heritage”, that coordinated the surveys of protected buildings and the design and implementation of temporary safety measures. This allowed the cooperation among different involved subjects (Ministry of Cultural Heritage officers, experts on structural engineering, architects and historians from Universities and private offices and fire brigade teams). The first level of the operating process was carried out on site by expert teams filling up dedicated survey forms for churches and palaces, developed by the Civil Protection Group GLABEC (a Working group for Cultural Heritage); the forms were based on the standardization of damage survey allowing for its immediate interpretation. The second level was based on the past experience in the field of temporary safety measures; the idea was to provide a technical and scientific support in order to assist the work of fire brigade, highly experienced professionals in the “emergency” field. After the first emergency phase the damages of the most important buildings were more carefully investigated and the possible damage progression constantly monitored. The paper presents the case of the Spanish Fortress in L’Aquila, severely damaged by the earthquake; the description concerns the definition of the damages and the interpretation of the activated collapse mechanisms. Finally the design of the provisional strengthening interventions and the on site diagnostic investigations are presented.