Details:
The Frassiney side in the municipality of Pontboset is affected by a potentially unstable rock body that risks of breaking loose and rolling downstream with potential involvement of the SR n. 2 statal road to Champorcher and the village of Savin.
The high level of danger is due to the presence of a large, strongly projecting block, locally cracked and in a condition of incipient detachment due to potential slipping and rolling.
The type and the extent of the instability have made it necessary to monitor continuously and in real time using a 25 m long DMS GV column in preparation for the planning and implementation of safety measures. During the works of putting the tie rods in operation, DMS instrumentation was used to ensure the safety of workers working above and below the block itself.
Once the tie rods were pulled together, the column was temporarily uninstalled to allow the laying of the roofing net and subsequently reinstalled to monitor the slope in the early post-operation phases.