Geological-technical study for the design of an underground variant of S.S. 52 “Carnica” in the Passo Mauria area (Carnic Alps)

This study aims to define a preliminary geological model of the Passo Mauria tunnel, designed as an alternative underground route to the current S.S.52 to ensure a safer connection over the top way Belluno (A27 Highway) Tolmezzo (A23 Highway), on which various tourist and economic activities revolve. The survey stage has allowed us to describe and represent the cartographic elements that describe the geology of the study area. The study has mainly focused on the investigation of the presumed entrances of the tunnel, characterized by specific geological and geomorphological conditions. The aerial photogrammetric survey supported the reconstruction of the geometry of discontinuities in the non-accessible areas. Besides, this study has allowed the definition of the possible behaviour of the rock mass subjected to the tunnel excavation and of sections with homogeneous mechanical properties. The drafting of a survey plan supplements the study to determine a geological and geotechnical model, for the subsequent investigation and design phases.