Report on earthquake-induced failures of rural buildings aimed at future preservation strategies

The rural landscape is undergoing rapid changes, and catastrophic events, such as earthquakes, can speed up this mutation, bringing to a loss of its traditional signs. In May 2012, two strong seismic events hit the Emilia Romagna region, in northern Italy. Those earthquakes caused several damages and collapses to historical rural buildings, highlighting their high seismic vulnerability. In this paper, damages and collapses collected in the aftermath surveys on 22 rural historical buildings, are presented and commented. It was observed that in the area hit by the earthquake few recurrent typologies are present, and buildings of the same typology showed similar damage mechanisms. Therefore, in order to define the most typical damages affecting rural constructions, the building stock has been classified in different categories, based on plan distribution and intended use of each building. The first criterion suggests considering isolated and composed buildings. The second separates the structures in dwellings for residential use, stable-haylofts and buildings used for other minor services. The outcomes presented in this paper allowed to identify the rural building typologies most vulnerable to earthquakes and to define recurring deficiencies for the various categories. In general, the main reasons of the collapses can be ascribed to lack of effective connections between orthogonal walls, poor connections between floor elements and walls, and excessive flexibility of floor diaphragms.