ABSTRACT
In tunnels design development, seismic action has always had a secondary role; past experience showed that, as structures with a circular shape in a continuous medium, confined and bound to the medium transmitting the action they are able to withstand the displacements and any induced stresses without suffering significant damage. The studies and knowledge in this field are relatively young and not codified as for classical buildings. In this work will be reported recent experience about seismic vulnerability of tunnels, gained on some works belonging to the Anas road network. Final purpose is to describe the conditions that determined damage, identifying elements that influenced the state of the damage detected and subsequently to introduce interventions to restore its safety and structural functionality. Specific relevance was recognized to seismic event characteristics, and to the peculiarities of the work itself, principally related to construction method and final quality obtained.
