Inspection of existing tunnels: development of an innovative methodology and use of special equipment for technical triage.

The research described in this paper illustrates trials of specific equipment used in the implementation of an innovative methodology for technical triage of existing tunnels, named VISIT (Visual Inspection for Safety-deficit Identification and Triage). Tests finalized for ANSFISA’ surveillance purposes were conducted by a group of researchers of the SPRINT-Lab laboratory of the University of Udine (Italy) and ANSFISA (Italian Agency for the Safety of Railways and Road and Highway Infrastructures) professionals. The tests were carried out in tunnels in the Friuli Venezia Giulia region (Italy), and they confirmed that the special equipment used for the VISIT inspections allows inspectors to perform a proper and cost-effective assessment. The inspections do not need the use of lifting platforms, requiring minor traffic restrictions. The final part of the paper highlights the critical reflections formulated by all the participants and the future developments of the research activities.