Architetture fortificate e terremoto. Influenza delle tecniche costruttive sui meccanismi di danno.

The main target of the study is to understand the relationships between the morphological and structural characteristics, the earthquake swarm and the mechanisms of damage, triggered by the Emilian earthquake of 2012, in some Emilian fortresses. The first step of the research has been to set the considered area from a geographical and seismological point of view. Then the evolution, the materials and the architectural technologies of the Emilian fortresses have been studied. Surveys and photographic evaluations have been done in order to understand the main morphological and structural characteristics of thirteen selected fortresses and to divide them into groups with similar features. By this large-scale subdivision, between the thirteen fortresses, the five case of study have been selected. During the surveys performed in the thirteen cases of study, seismic damages have been observed. The damage mechanisms checked have been classified in a chart. Only for the five cases the damages of the chart have been studied in detail and they have been divided into architectural elements. The outcome of the study is that each mechanism of damage was not caused just by one reason but by several ones, variously combined. The most important reasons are: the diachronic changes of the buildings during the time, the mutual position of architectural elements in a fortress, the building defects, for example when there aren't elements of connection between different levels in the walls, the poor quality of building materials used, the incompatibility of the restoration interventions made during the XX century and the relationships between the cases of study and the peculiarity of the environment, as for example the high level of humidity and the aquifer not very deep. Furthermore the characteristics of the earthquake swarm have influenced the characteristics of the observed damages.