SEISMIC DAMAGE AND VULNERABILITY ANALYSIS OF HISTORICAL CONSTRUCTIONS

In April 2009 several earthquakes struck central Italy, devastating L’Aquila and the surrounding villages in the Italian region Abruzzo, causing inconveniences and damages to the local population. The heavy structural damages caused by the sequence of shocks and aftershocks during earthquakes can still be observed on the buildings yet; both the high-intensity oscillations and the intrinsic peculiarity of the earthquake itself were the causes of such severe damages. Not only did the earthquake affect a particularly wide and patchy area, but its devastating effects were magnified by the vibrating contribution.
The aim of this paper is to help the professionals involved into reconstruction works, who often acts without the necessary knowledge on the amount of the damage. The current Italian rules (NTC 2008), for instance, do not take into account  the possible vibrating contributions of the earthquake and the Existing buildings’ section  (Chapter 8) requires a thorough study on the knowledge level of the work (LC).
Therefore, the main purpose of this research paper is to present a procedure able to define, from a qualitative perspective and taking into consideration already existing models, the damages caused by a generic earthquake to the existing buildings. The focus will be not only on the immediate post-earthquake effects, but also on the evaluation of the propagation  process of damage at a later time.
The procedure will be based on previous experiences of seismic damage already existing in the literature: such experiences will be reorganized in an organic and systematic way to make the procedure easily applicable by professionals.
The following project is based on a series of experiences collected in areas affected by the earthquake, such as Abruzzo in 2009: some study cases were chosen randomly in the panorama of the crater seismic in order to face most effects induced by the phenomenon. 
Since the analysis perspective depends on the type of building under review, we decided to deal only with churches and monasteries because of their easy detection area and their widespread presence in Abruzzo.
Moreover, the damage and the destruction of these important buildings caused the local population  a loss of landmarks. This reason, as well as the historical and social ones, explains why a study on religious buildings affected by the earthquake can be useful.