CRITERIA FOR THE VULNERABILITY ANALYSIS OF STRUCTURAL AGGREGATES IN HISTORICAL CENTERS

The need to define earthquake prevention and intervention strategies, in order to limit dramatic consequences for the society, has acquired a high priority in countries where, like in Italy, a large number of historic masonry buildings (listed or not) are located in areas with medium to high seismic hazard. From the point of view of the level of safety to be reached through interventions, the concept of improvement, as opposed to that of full strengthening, is nowadays widely accepted in the case of monumental heritage; what is still lacking, in many cases, is a procedure for the vulnerability analysis, as a synthetic evaluation tool for the definition of intervention priorities. In a modern perspective, where territorial planning is conceived as a safety project for the territory, the seismic vulnerability analysis should not be confined to specific technical documents, but should rather be considered at a general level; in this way only, indeed, the issue of seismic risk could acquire widespread knowledge and awareness in the population, also pushing urban planning in the direction of general programs for the increase of seismic safety. In the above perspective, revised criteria have to be developed for a global vulnerability assessment, to be introduced at a general level in territorial planning. Considering that seismic vulnerability analyses are strictly dependent on specific building typologies, attention has been focused, in the present study, on to the case of structural aggregates in historical centers, thus following the needs of the Italian Civil Protection Agency in relation to seismic prevention activities in historical towns. The research, which is still in progress, takes advantage from the application to a few study cases, suitable for the experimental testing of procedures.