The intervention concerns the safety upgrading and rehabilitation of the Pietra Liscia Viaduct, located along Provincial Road SP 180 in the Municipality of Lipari, a strategic infrastructure for mobility on the island and for connections between inland areas and the coastal zone. The project aims to improve the safety, functionality and durability of the infrastructure within a context affected by significant structural, geotechnical and hydraulic issues.

The existing viaduct, approximately 170 m long, consists of a reinforced-concrete structure with a grid system and Gerber hinges. The intervention includes the rehabilitation of the infrastructure layout through new structural works, upgrading of the road platform and the introduction of modern safety systems.

Particular attention is given to slope stability, as the area is characterized by pumice and pyroclastic deposits subject to surface erosion, gullies and localized instability. The project therefore includes measures aimed at slope consolidation and protection, with the objective of limiting the development of erosion processes and ensuring the safety of the infrastructure.

Works are also planned for the management of stormwater runoff, through collection, conveyance and controlled discharge systems, with the aim of reducing erosion phenomena and improving the hydraulic protection of the area.

The design activities include topographic surveys, structural, geotechnical and geophysical investigations, static and seismic assessments, as well as geotechnical and hydraulic studies, all aimed at defining an integrated intervention consistent with the characteristics of the site.

Overall, the project integrates structural works, geotechnical interventions and hydraulic drainage systems, with the objective of increasing infrastructure safety, reducing hydrogeological risk and ensuring the continuity and reliability of traffic along SP 180.