TRADITIONAL BUILDING CRITERIA IN THE LEFKADA ISLAND: PECULIARITIES OF THE FOUNDATION SYSTEM

The traditional construction technique in use in the town of Lefkada, Greece, has attracted scientific interest since the end of the nineteenth century, when British engineers were called to draw up a report of the damage caused by the earthquake that had occurred in the Ionian Islands in 1825. The British government, which at that time exerted power over the area, in recognition of the effectiveness proven by the structural system adopted in the town traditional buildings, ordered to apply the same concept both for restoration and for new construction, in accordance with the rules specified in a Code of Construction (1827). Inside the Mediterranean area, the Ionian Islands are exposed to specially high seismic hazard, so that the effectiveness of the Lefkada building technique has been observed and studied thor-oughly; recently, after the earthquake occurred in 2003, detailed analyses of the above ground structure and of the relative design details have been published [5,1,4]. However, the knowledge of the underlying foundation system has been lacking so far. The interest in this problem comes from the softness of the ground which is typical of the area where the Lefkada town was erected: the Venetians created the town ex novo, moving the inhabitants from the Castro of Santa Maura to a marshy coastal area, which had been reclaimed. The problem of the foundation settlement, therefore, has always had to be considered in the design phase. On the basis of on-going studies, in this paper it is shown that the Lefkada building tradition pe-culiarities are present not only in the above ground structure, but in the foundation system as well. Two alternative solutions in use for the foundation structure are described, together with the construction technique and the employed materials. In the paper it is also highlighted that the adoption of effective building criteria, able to oppose adverse environmental condi-tions coming from both earthquakes and poor soil conditions, was based exclusively on the use of locally available resources and on the local building tradition.