Brenner tunnel: comparasion between the geological project model and the field survey data in Mules 2-3 section = Galleria del Brennero: confronto tra modello geologico di progetto e situazione rilevata nel corso degli scavi nella tratta Mules 2-3

In this thesis it will be described, starting from the design phase and carrying on with the progress in the building site, one of the most important underground work in Europe: the Brenner tunnel. The personal work is based on an 3 months internship sponsored by S.W.S. Engineering S.p.a. at the Mules construction site B.T.C. (Brenner Tunnel Construction), where there will be acquired the information about the construction site organization and the geological activities necessary for the progress of the work. After a general description we will go deeper in detail, examining the different excavation and monitoring types of data acquired during the excavation progress. It will be also given a general illustration of the fault systems and the fault propagation forms in the work area with its damage zones. The expected data are going to be outlined with the data collected on site, to verify their congruity, in terms of both geomechanical values, like RMR (Rock Mass Rating) and GSI (Geological Strenght Index), and identifying the extension of the large fault zone that the work crosses (Sprechenstein Mules Fault Zone, SMFZ). This one, in the sector taken into consideration, extends for over 700 meters from the progressive 47+440 to the progressive 46+735, referring to the Est Gallery. The progress data have been provided by the company that is carrying out the works (BTC) and, at some progressive, have been compared with the geomechanical data collected directly on the excavation front. Finally it will be proposed a new geological profile of the fault zone (SMFZ), based on the interpretation of the boreholes carried out during both the project time and the excavation and also the available geological maps of the area and this profile will be compared with two different geological sections (forecast project section and the section carried out by Bistacchi et al., 2010), that show important differences of interpretation of the zone taken into account, will be compared. At the end it will be drawn conclusions regarding the preliminary geological survey methods.