Piora syncline successfully conquered at first attempt

Today, October 15, 2008, the tunnel boring machine in the east tunnel of the Gotthard Base Tunnel cut through the last few meters of the geologically challenging Piora syncline and reached the Medels granite. The results of the exploratory boring system of the nineteen-nineties as well as the exploratory bores of September 2008 have thus been completely confirmed. No particular problems occurred during the traverse.

On September 28, 2008, the tunnel boring machine in the east tunnel cut through the first metres of the Piora syncline. Just over two weeks later, on October 15, 2008, it reached the Medels granite that lies to the north of the Piora. Advancing at a rate of 10 m per day, the tunnel boring machine made good progress through the approximately 150-metres-long Piora syncline.

The rock behaviour was stable. No notable deformations were detected in the dolomitic rock, and no water was encountered.

In the east tunnel, a further 9.4 km of rock remain to be cut before breakthrough takes place between Faido and Sedrun. The drive in the west tunnel is around 1600 m behind that in east tunnel, and is expected to traverse the Piora syncline in the first quarter of 2009.

Provided that all progresses as planned, the main breakthrough of the Gotthard Base Tunnel will take place in the first half of 2011. Commercial operation of the Gotthard Base Tunnel with scheduled train services is expected to start at the end of 2017.