Seismic Isolation in Newly Built Bridges in Italy: Historical Development, Regulations, and Recent Applications

Seismic isolation is a well mature technique to protect structures against earthquakes, allowing to achieve a level of safety not possible with conventional systems. The Somplago viaduct on the Udine-Tarvisio highway, built in 1976, was the first seismically isolated bridge in Italy. Its good performance during the strong shocks, which hit the viaduct when it was still under construction, encouraged the use of seismic isolation in bridges. The development of applications in Italy was initially quite slow, due to the delay in considering this new technology in technical standards. Significant developments occurred following the major seismic events that affected the country. Today, seismic isolation is almost always used for new construction projects and, especially, in major cases, such as those illustrated in this paper.