Klaus Tunnel Chain: Ground support products stabilize excavation of eastern tubes
The A 9 Pyhrn Motorway in Austria is an important North-South link. One of its sections is the Klaus Tunnel Chain. The approx. 8 km long section of the A 9 is located around 130 km east of Salzburg and was originally built with one lane in each direction. At the end of 2013, the completion of the section began with the construction of new bridges that also served as access roads for the construction of the second tunnel tubes.
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Section 4 included the eastern tube of the 2.2 km long Klauser Tunnel as well as the eastern tube of the 0.4 km long Traunfried Tunnel. The Klauser Tunnel is being excavated from an intermediate heading, with a 28 and a 70 m long section in the North being built using the open cut method and a 36 m long section being built using the cut-and-cover method. The actual excavation work of the 1,857 m long tunnel started in May 2015 and is being realized using the mining construction method.
The crown of the eastern tube was driven in advance because it served as an escape route for the existing western tube. Bench and invert heading were used for driving the tunnel. The excavation of the Traunfried tunnel was carried out successively in crown, bench and invert.
For stabilizing the tunnel driving work in both tunnels, DSI supplied the following high quality ground support products:
- OMEGA-BOLT® Expandable Friction Bolts with anchor plates
- 25 mm Ø SN Anchors in lengths of 2, 3, 4 and 6 m
- R32-250 Ø and R 32-280 DYWI® Drill Hollow Bar Anchor System in lengths of 2, 3 and 4 m
- R32-250 Ø DYWI® Drill Self-Drilling Spiles
- 25 mm Ø steel spiles in lengths of 3 and 4 m
- Type AT – 114 Pipe Umbrella System with threaded connections including drilling unit and accessories
The 2.9 km long Spering Tunnel as well as the 0.8 km long Falkenstein Tunnel are located in section 5. Carbonate rock with gravel, limestone and clay marl prevail in this part of the northern Tyrolese limestone Alps. The Eastern tube of the Spering Tunnel was excavated using bench and invert heading along the complete tunnel length. In two locations, the tunnel tube was widened to accommodate cut-outs. The new and the existing tunnel tube are connected via eight walkable and two drivable crosscuts. At the eastern tube of the Falkenstein Tunnel, excavation and stabilization are carried out in the total cross section. Here, both tunnel tubes are connected via two walkable crosscuts.
In both of these tunnels, the following ground support products were used for safe excavation in partly brittle rock:
- OMEGA-BOLT® Expandable Friction Bolts with anchor plates
- 25 mm Ø SN Anchors in lengths of 2, 3, 4 and 6 m
- R32-250 Ø and R 32-280 DYWI® Drill Hollow Bar Anchor System in lengths of 4, 6 and 12 m
- 25 mm Ø steel spiles in lengths of 3 and 4 m
- R32-210 Ø, 3 m long IBO Self-Drilling Spiles
- Lattice girders incl. angle connections and accessories
- Arches
- Type AT – 114 Pipe Umbrella System with threaded connections including drilling unit and accessories
With the help of the ground support products supplied by DSI, all of the tunnel tubes were excavated safely and within the planned schedule.
References
Spital am Pyhrn, Upper Austria, Austria, Europe - Klaus an der Pyhrnbahn, Upper Austria, Austria
Structure Types
- About this
data sheet - Product-ID
7343 - Published on:
30/03/2016 - Last updated on:
17/11/2021