Seismic isolation and other antiseismic systems: Recent applications in Italy and worldwide
Seismic Isolation and Protective Systems
Over 10,000 structures have been protected in the world by antiseismic systems and devices, namely by seismic isolation and energy dissipation systems, shape memory alloy devices and shock transmitter units. Such structures are located mostly in Japan, but they are more or less numerous in over 30 other countries as well -for example, in the Peoples' Republic of China, the Russian Federation, the United States, Italy and even countries with very a limited population like Armenia and New
... nia and New Zealand. The number of such systems and devices is increasing everywhere, although the extent of their use is strongly influenced by earthquake experience and the features of the design rules used. Applications have been developed for both new and existing structures of all kinds: bridges and viaducts, civil and industrial buildings, cultural heritage and industrial components and installations, including some high risk plants. The use of such systems in a civil context already includes not only strategic structures (civil defense centers, hospitals, etc.) and public ones (schools, churches, commercial centers, hotels, airports, etc.), but also residential buildings and even many small private houses. This paper provides an overview on the dissemination of such applications worldwide, based on the most recent information available to the authors. Particular attention is paid to Italy, in the context of specific seismic events -for example, the Molise and Puglia event (October 31, 2002) and that of Abruzzo (April 6, 2009) -and the lessons learned from them. Information is also provided on the features of the Abruzzo event, the development of national seismic design rules (which became obligatory only after that event) and some very recent decisions on the part of the Italian government which promote the use of seismic isolation and energy dissipation to enhance the safety level of structures, especially schools. The paper focuses mainly on seismically isolated buildings, but some information is also provided on the use of other antiseismic systems, devices, and applications to structures other than buildings.