BarChip Fibre Reinforced Shotcrete is part of the ground support systems used at the Brenner Base Tunnel.

BarChip macro synthetic fibre reinforced shotcrete is providing ground support to the conventionally excavated sections of the Brenner Base Tunnel’s (BBT) largest construction lot, Mules 2-3. This includes the Southbound Drive of the main rail tunnels and supporting tunnelling works.

The BBT project has been broken up into 7 construction lots, the largest of which is Lot H61 Mules 2-3 on the Italian side. The 993 million Euro contract for Mules was awarded to the bidding consortium Webuild S.p.A., Ghella S.p.A., Oberosler Cav Pietro S.r.l., Cogeis S.p.A. and PAC S.p.A. with works starting in 2016.

Lot Mules 2-3 comprises 65 km of tunnelling works, made up of 39.8 km of main tunnels, a 14.8 km exploratory tunnel, the 3.8 km approach to the emergency stop in Trens and 6.9 km of safety and logistics tunnels. The circa 17 km Northbound drive, emergency stop and exploratory tunnel at Mules have been excavated by TBM. The remaining tunnels, including the 5 km Southbound drive are being excavated via drill & blast.

BarChip macro synthetic fibre was chosen as the primary reinforcement solution for the shotcrete ground support in the drill and blast excavated tunnelling. The shotcrete was mixed on-site via an internal concrete plant.

Project Summary

The Brenner Base Tunnel (BBT) is an ambitious 55 km twin tube railway project connecting Innsbruck (in Austria) to Fortezza (in Italy). The BBT will connect with the existing 12.7 km Inn Valley tunnel to form the largest underground railway connection in the world.

In total over 230 km of new tunnel systems will be constructed, excavated with a mix of TBM and drill and blast methods. The tunneling works include the 8.1 m diameter main tunnel drives, a 5 m diameter exploratory tunnel, 3 emergency stop tunnels, 4 access tunnels, service and logistic tunnels and cross passages every 333 m.