Bosruck Tunnel second bore: a challenge for sequential tunnelling in various geological formations / Zweite Röhre Bosrucktunnel: Zyklischer Vortrieb in unterschiedlichen geologischen Formationen

The construction of the second bore of the Bosruck Tunnel is very much influenced by the experience gained in the first bore, which affects the tunnel advance and also support. The west bore has a total length of 5,424 m and is being sequentially tunnelled from both portals at the same time. In addition to the main tunnel, there are eleven crosscuts to be excavated. The article reports on the start of work from the beginning of January 2010 until September 2010 and gives an overview of the schedule and work preparation for the forthcoming excavation and support works in the various rock formations.