RECENT DEVELOPMENT AND APPLICATION OF SEISMIC ISOLATION AND ENERGY DISSIPATION SYSTEMS, IN PARTICULAR IN ITALY, CONDITIONS FOR THEIR CORRECT USE AND RECOMMENDATIONS FOR CODE IMPROVEMENTS

Over 16,000 structures have been protected in the world by seismic isolation (SI), energy dissipation (ED) and other anti-seismic (AS) systems. They are located mostly in Japan, but they are more or less numerous in over 30 other countries, as well, including Italy. Their number is increasing everywhere, although application is strongly influenced by earthquake lessons and the features of the design rules used. Such an application has been performed to both new and existing structures of all kinds. In a civil context it already includes not only strategic and public structures, but also residential buildings and even many small private houses. This paper: (a) summarizes its most recent progress, in particular for the isolated buildings in Italy; (b) stresses the conditions for the correct use of SI, by also providing some examples of errors made during construction of Italian isolated buildings; (c) mentions some recommendations recently approved by the VIII Commission of the Italian Parliament and the Government, to ensure such a correct use, by modifying the design rules that are currently adopted for the isolated structures; and (d) illustrates an even more recent initiative of the President of the aforesaid commission to enhance the seismic protection of high risk chemical plants in Italy, in particular through the use of SI.