Design Code Progress and Conventional Seismic Safety Improvement in Italy

Abstract

In Italy it is acknowledged that the modern era of seismic design started after the 1908 Messina earthquake. Ever since, design codes and design hazards have had a relatively continuous evolution, following the international development of earthquake engineering, a process that is continuing nowadays. On the other hand, most of the existing building stock, mainly composed of reinforced concrete or unreinforced masonry buildings, is much more slowly renovated, so that these structures are designed with now obsolete or without any seismic provision. Considering that codes, even those at the state-of-the art, do not explicitly control the reliability implied by design, the safety achieved by the progress in seismic design has not been quantified systematically. This is the scope of the study presented in this technical note that, resourcing from the results of a large research project, quantified the fatality rates, computed according to three different methods, following the changes in building codes in Italy. Although highly conventional and mainly useful for relative comparisons, the results show the systematical improvement of safety achieved by evolving seismic design, with the largest increment attributable to the current code, which is based on the same principles as Eurocode 8.