ABSTRACT
The Milan Genoa high speed/high capacity line is expected to realize 90 km length tunnel; about 60% of them should be excavated in a shale formation called “Argille a Palombini”This shale formation has characterized to have a low metamorphic range and, moreover, inside the rock mass sudden mutations of the tectonics stress are observed.The monitoring of these stress and daily viewing of excavations has underlined how this typical geotechnical behavior didn’t influenced the excavation features, but it has modified the tunnel profile deformation, in some case intensely.Inside the paper, this particular behavior and the resulting technical difficulties are therefore discussed and analyzed. The design tools and solution, like geological and geo-technical profiles and ground excavation consolidation, were demonstrated a good means to understand and solve the advancement in critical conditions.
