ABSTRACT
The Brenner Base Tunnel will be 64 kilometers long and will be the centerpiece of the Scandinavian-Mediterranean TEN-T Corridor from Helsinki to Valetta (Malta). It will comprise two single-track rail tunnels with a service and drainage gallery in between. The primary focus in this paper is on the construction of the 15km long exploratory tunnel Ahrental using a well-adapted TBM concept. Tunnelling started from Austrian Ahrental towards the Italian border in challenging terrain using a 7.93m-diameter Gripper TBM. The geology along the section is characterized as extremely challenging with quartz phyllite and shale and high overburden of up to 1300m. Moreover, numerous fault zones were predicted along the drive with expected loose to friable rock mass. The paper addresses in particular the special TBM design and project experiences with the operation of a Gripper TBM in challenging rock mass.
