Eagle tunnel
The Adlertunnel is a 5.3 kilometer long double-track railway tunnel in northern Switzerland near Basel . It serves to relieve the Hauenstein line between Muttenz and Liestal and is mainly used by express trains of the InterCity and InterRegio categories as well as ICE and TGV . Whenever operationally possible, freight trains that are traveling from Germany in the direction of Olten and do not have to pass through the Basel-Muttenz marshalling yard are also directed through the Adlertunnel. Indirectly, it is also a feeder to the Gotthard Railway . After construction began in 1994, it was put into operation in 2000 and shortened the travel time from Basel to Olten by two minutes.
location
At the height of Muttenz, the double-track new line branches off from the main line (see Bözbergbahn and Hauenstein line ). It stretches towards the southeast and passes under the Lachmatt. The eagle , which gives the tunnel its name, is an elevation of the Jura Mountains at 535 m above sea level. M. at six hundred and nineteen thousand four hundred forty-seven / 261 772 ( Swiss coordinates ).
construction
Construction work on the tunnel lasted from 1994 to 1999, and it was divided into three construction sections, the north opencast section (841 m, Pratteln side ), the mining tunnel (4264 m) and the south opencast section (223 m). The first two sections made high demands on the project planning, as the tunnel leads through different geological layers. In the north these are loose rock over calcareous layers. In the past, rock salt was mined at a depth of around 150 m . In the mining part of the tunnel there are zones with swellable, anhydrite-containing rock. The mining part was a Herrenknecht - TBM ascended at around 12.50 m outer diameter. Commissioning took place in December 2000.
Repairs
Subsidence due to leaching in rock salt layers
In the North Tagbaustrecke were after commissioning translations found. In this area, the opencast tunnel has now been reduced by up to 30 cm to a length of around 150 m. Previously mined rock salt layers had washed out at a depth of 150 m and led to a light sinking funnel . The small overburden over the opencast tunnel was not carried out over a length of approx. 150 m in this area. The tunnel has now been raised hydraulically three times .
Elevations through anhydrite swelling
In a tunnel section approx. 40 m long and approx. 1000 m from the north portal near Pratteln , deformations ( uplifts ) were recorded in the rock . These resulted in the transition from anhydrite to gypsum in mountain water . The swelling pressure of the mountains led to uplifts of 6 to 7 cm and slightly ovalized the inner vault. At this point there was a break in the TBM tunneling. The cover there is therefore inhomogeneous and probably slightly water-bearing. The tunnel is specially monitored in this area.
A repair was planned in a project competition and started at the beginning of 2010: In the affected section, the tunnel vault will be removed piece by piece, behind which a 6 meter high and 3.5 meter wide concrete block will be installed. The concrete bar is also anchored in the rock with steel anchors and micropiles up to 15 meters long. In the future, this construction should absorb the pressure from the swelling rock layer and thus prevent the tunnel floor from lifting any further. The original closing date at the end of October 2010 could not be kept because the rock was again unstable; it was re-advised for July 2011. The renovation will become more expensive than the initially planned 15 million Swiss francs .
See also
Sources, individual references
- Repair of the Adlertunnel (PDF; 290 kB) TEC21 41/2007, pp. 8–10
- ↑ Regine Ounas-Kräusel: Work is underway inside the mountain , badische-zeitung.de, Lokales, Lörrach & Dreiland, October 14, 2010 (accessed October 17, 2010)
Coordinates: 47 ° 29 '52.3 " N , 7 ° 42' 40" E ; CH1903: six hundred and twenty thousand five hundred thirty-two / 260824