Gotthard Base Tunnel: TBM restarts in Faido west tunnel

On 4 March 2010 excavation had to be stopped in the west tunnel of the Gotthard Base Tunnel some 9 km from the Faido multifunction station due to a rock inrush, and exploratory bores had to be performed to determine the length of the fault zone. To allow the tunnel boring machine (TBM) to be restarted, the loose material in front of and above the cutterhead of the TBM was solidified with cement through an injection niche from the parallel east tunnel. At the same time, also from the east tunnel, a further tunnel was excavated to the west tunnel and then driven backwards so that on July 22,...