SEISMIC VULNERABILITY ANALYSES OF THE HISTORICAL CENTRE OF SPLIT (CROATIA)

Historical centre of Split (Croatia) has been built in the Palace of Roman Emperor Diocletian, often over the ruins or the demolished buildings of earlier periods. This small town, characterized by narrow streets of tall buildings in a sort of labyrinth, represents a extraordinary historical heritage of Split, which has been included, for this reason, in the Unesco list of fundamental historical centres to be preserved. Over 17 centuries of history are documented by different structural typologies, represented mainly by masonry walls, constituted by similar stone bricks (organized in one or two layers plus a poor concrete internal layer) and mortars of different quality, as well as wooden floors and roofs. An updated version of specific software already developed by University of Padova for masonry buildings was adopted for the analysis of seismic vulnerability of the historical centre of the town. This is made of a very large number of structural aggregates built up, in many ages, in the Diocletian's Palace, between the forth century a.C. and the nineteenth century a.C., which represent a extraordinary historical heritage. The survey procedures and the corresponding analyses of vulnerability, in this phase, have interested over six hundred masonry buildings, which belong to all the quarters zones of the Diocletian's Palace. Several in-situ and laboratory tests have been carried out on different masonry walls, with different typologies (from the Diocletian’s walls of the 4-th century, to 8-th century ones, to medieval ones, until 19-th century ones), in order to calibrate the use of the expert system and to became possible the evaluations of seismic vulnerability for the current state and for different hypotheses of structural retrofitting