Railways & Subway

BBT: Mules I

Brenner Base Tunnel
Owner/client PAC S.p.A.
Type of service Construction Design
Location Autonomous Province of Bolzano, Mules
Period 2012 - 2014
Cost € 50.000.000

This lot is the continuation of the preliminary works for the construction of the Base Tunnel on the Italian side.

Its key features are the creation of large cavities (TBM Chambers, Logistic Chamber, Ventilation Chamber), the presence of several intersections among the cavities, and above all the Exploration Tunnel crossing the Periadriatic Tectonic Lineament.

Twin rail tunnels

Single track (L=2x1200 meters), approx. 10 meters in size excavation with conventional methods, connected with 3 transversal by-pass.

Exploration tunnel

Exploration tunnel (L=1200 meters), approx. 6 meters in size excavation with conventional methods.

2 chambers

2 chambers for TBM (180 meters long, 22 meters in diameter, 18 meters high).

Logistic chamber

Dimensions: L=40 meters, D=20 meters, H=18 meters.

Ventilation chamber

imensions: L=20 meters, H=18 meters; connected to outside with an air shaft (D=6 meters, H=47 meters) and connected at 'Mules Window' with 2 branches tunnel (dimensions: 11x10 meters).

Various tunnels

Various tunnels of the underground logistic node of Mules.

The excavations start from the south portion of the lot in the Brixen Granite with overburden of 1200 m (Mules node, Chambers, south portion of the Exploration Tunnel and of the Line Tunnels) and, after crossing the Pusteria Fault (south margin of the Periadriatic Lineament, with approx. 30 m thickness), continue through the Lamella di Mules (Mules Tonalites), reaching in the final 300 m of the Exploration Tunnel the tectonized rocks of the Mules Fault (north margin of the Periadriatic Lineament), made of a disorderly succession of shale carbons, tectonized paragneiss, quartzite, anhydrites with subvertical arrangement of the various portions.

To cross the tectonized areas, special excavation sections have been designed, taking into account the potential mass deformations and the development of significant loads resulting from the poor characteristics of the material and the 600-700 m high overburden.