Emergency hazard mitigation works along the railway section affected by a collapse of granite blocks with a maximum unit volume of approx. 19mc. Initial scouting activities by helicopter and on foot of the areas of collapse, photogrammetic survey, geomorphological and geomechanical survey, Laser Scanner survey of the collapsed blocks to determine their shape and volume, deterministic and statistical analysis of the rock mass discontinuities and rockfall simulation to reconstruct the dynamics of the event (back analysis) and to size the defense work (vallo/tome system). Performing exploratory surveys, VpVs seismic surveys (tomographic refraction and masw2D) and HVSR tests to define the geological and geotechnical model, preparatory to the design of the defense structure. Clearing and dislodging of dangerous boulders present along the rocky outcropping strip approx. 400 meters upstream of the railway line. Two tomes with a total length of 336m were designed and erected to protect the line, with downstream face made of cyclopean boulders, reinforced soil, and natural escarpments, and upstream face supported by cyclopean boulders with maximum heights of 9m. During the works, in order to ensure safety in the site areas, monitoring systems were installed for the most voluminous and deemed most unstable rock masses (bar and wire strain gauges), connected to warning and alarm systems (fixed and mobile sirens and flashing lights). As an implementation of the surveillance systems, two high-resolution cameras were installed on the slope, close to the work site, which enabled the remote capture of images at predefined intervals and on demand, allowing to view the status of the work at any time, even outside the work site's operational shift. The materials used in the construction of the works and the laying systems were verified, performing in situ geotechnical tests and laboratory tests.
