Damage assessment of churches after L'Aquila earthquake (2009)

L'Aquila earthquake, which occurred on April 6, 2009, proved the high vulnerability of cultural heritage, with particular reference to churches. Damage assessment in the emergency was carried out on more than 700 churches with a methodology aimed at recognizing the collapse mechanisms in the different architectonic elements of the church. The method was developed after the earthquake in Umbria and the Marches (1997) and has been widely used in the last decade; this approach is also very useful for seismic prevention, as it allows one to single out the most vulnerable structures. Some examples are presented in this paper, representative of recurrent damage in the main elements of the church: the fa double dagger ade, the roof, the apse and the belfry. It emerges that, for a correct interpretation of damage and vulnerability, it is necessary a deep knowledge of local construction techniques and of the historic transformation sequence. Moreover, the bad behaviour of churches strengthened by modern techniques, such as the substitution of original timber roofs with stiff and heavy r.c. slabs, was observed. Starting from the observation of some case studies, the paper achieves some worth results, which may be useful for correctly driving future strengthening interventions.