Project overview Itenbau AG carried out the move of the tunnel boring machine “Carla” over a distance of around 300 metres into a cavern. The excavation works took place in the Gotthard massif in 24-hour operation with a total of 120 people involved. About 370,000 tonnes of rock were excavated, with an average advance of around 17 metres per day and a peak of 45.4 metres per day.
Challenges
The tunnel boring machine, weighing about 680 tonnes, travelled on a gradient of 2.6% and through a curve radius of around 150 metres.