The great tunnel of the Apennines (Italy): a lesson from the past
In the early XX century, a long base-tunnel (the Great Tunnel of the Apennines - GTA - 18.507 km long) was executed between Bologna and Firenze (Italy). During excavation, large water inrushes, methane inflows and swelling events occurred, with many injuries and casualties. In this paper, we present a re-visitation of the main geological concerns of the GTA in order to understand, at the light of the new geological maps at the scale of 1:10.000, recently surveyed, the geological features responsible of those serious accidents. This geological re-visitation of the GTA led to draw an update geological cross-section along the tunnel axes. This has allowed to understand the geological features of the accidents and to learn their interaction with tunnelling. This paper shows how a critical and contemporary re-reading of past-experiences can greatly contribute in the phase of planning new complex works in the same geological context.