Seismic risk and conservation of architectural heritage in the Mediterranean basin

摘要

The architectural heritage which has accumulated over thousands of years in the Mediterranean basin comprises a rich and complex record of the history of successive civilizations, embodying their long, intricate development. This heritage suffered considerably from the upheavals which characterised last century, and its conservation represents a major cultural commitment. While the Mediterranean basin as a whole has always been at great risk from seismic events, the ancient conception of building never failed to take this hazard into account. The advent of modern "structural engineering" based on a technical-scientific approach to construction has led to calculation of seismic risk for new constructions and the formulation of complex norms. Regrettably, seismic engineering has not paid sufficient attention to the historic built environment, and the few indications which are to be found in official regulations are confused and contradictory. There are problems concerning private property, as well as of access, safeguarding and structural modifications. This has led to interventions which are totally out of keeping with the ancient conception of building in monuments, and a widespread, deleterious cementification of the historic built environment. This has profoundly altered the nature of ancient monuments as documents of material history. In the last twenty years some researchers have sought to contrast this technocratic approach, particularly in Italy, where the concept of "structural improvement" has been elaborated to safeguard historic buildings and contexts. In this paper we first illustrate the damage done to some exemplary monuments, and go on to examine the inadequacy of current regulations, suggesting a simple approach to anti-seismic safeguarding for ancient architecture. We refer briefly to a series of important cases where it has been possible to apply the criteria elaborated and adopted by the Italian Ministero dei Beni e delle Attivita Culturali. We end by outlining the great difficulties caused by current trends in the economy for a compatible conservation of the built heritage.