Schwarzer Berg tunnel
| Schwarzer Berg tunnel | ||||
|---|---|---|---|---|
 East portal, direction Schweinfurt
|
||||
| traffic connection | Federal motorway 70 | |||
| place | Eltmann | |||
| length | 738 m / 722 m | |||
| Number of tubes | 2 | |||
| Largest coverage | 66 m / 72 m | |||
| construction | ||||
| building-costs | € 8.2 million / € 18.4 million | |||
| start of building | 1984/2002 | |||
| completion | 1986/2004 | |||
| location | ||||
|
||||
| Coordinates | ||||
| West portal | 49 ° 58 ′ 42 " N , 10 ° 37 ′ 45" E | |||
| East portal | 49 ° 58 ′ 40 " N , 10 ° 38 ′ 21" E | |||
Map with all coordinates: The Schwarzer Berg tunnel is part of the federal highway 70 and is located near the Lower Franconian town of Eltmann in the Haßberge district . The motorway tunnel consists of two tubes with two lanes each and crosses the Black Mountain.
To minimize the interference in the Wildbach valley and the 330 meter high Black Mountain, the tunnel was planned and built in place of a 50 meter deep cut. This is followed by the 165-meter-long Wildbachtalbrücke in the west and the 1055-meter-long Eltmann Bridge in the east .
North tube
Construction work on the 738-meter-long north tube began in October 1984. The official tunnel construction followed on December 12, 1984. The tunnel sponsor was Monika Hohlmeier , the daughter of the then Bavarian Prime Minister Franz Josef Strauss .
The tunnel was excavated from the east portal with a cross-sectional area of 93 square meters with a staggered cross-section subdivision into dome , bench and bottom . The tunnel excavation of 68,000 cubic meters was carried out with lengths of up to 1.5 meters in blasting and in some areas with a tunnel excavator . Shotcrete lining according to the new Austrian tunnel construction method was used to secure the excavated cross-section . The tunnel drive ran continuously around the clock for ten days with a subsequent four-day break. The breakthrough of the dome was on April 15, 1985 and the excavation work ended in the summer of the same year.
The tunnel has a closed shotcrete outer shell on which a seal is applied, followed by a 30 centimeter thick, largely unreinforced, vaulted concrete inner shell. The inner shell was manufactured in ten-meter-long sections, which were divided into the base vault and the dome vault. The tunnel has an eight meter wide roadway and a driving height of 4.5 meters.
The building was handed over to the client on July 17, 1986, and commissioning followed on November 6, 1987 with the completion of the Main Bridge. The construction costs amounted to 16.5 million DM.
After the commissioning of the south tube in November 2004, a general overhaul of the north tube followed. The entire equipment as well as the roadway and the drainage systems were replaced. The cost of the modernization was 2.5 million euros. Since July 29, 2007, both tunnels have been in operation for the first time without oncoming traffic.
South tube
In September 2002, construction work began on the 722-meter-long south tube. The official tunnel stop was on December 12, 2002. The tunnel sponsor was Uta Sinner, the wife of the then Bavarian State Minister Eberhard Sinner .
First of all, the dome jacking was carried out on the tunnel, which had a cross-sectional area of 102 m². After the dome on the west portal had penetrated in June 2003, a special suggestion by the commissioned working group was followed by the bench and bed excavation, stepping backwards. The tunnel excavation was 79,000 cubic meters. The two-shell tunnel lining was carried out in the same way as the north tube, but with a concrete inner shell 40 centimeters thick in the normal areas. The shell, which also comprised three cross tunnels to the north tube, was completed in April 2004. The traffic was opened on November 11, 2004. The costs amounted to 15.5 million euros for the shell and 2.9 million euros for the factory equipment.
safety
The two tunnel tubes are connected to each other by three cross tunnels with fire protection doors. The distance between the security gates is a maximum of 211 meters. Eight jet fans for artificial ventilation are installed in each tube. The motorway tunnel is remotely monitored with 25 cameras by the traffic and operations center of the Northern Bavaria Motorway in Nuremberg-Fischbach. The company building is 300 meters from the west portal. It is dug into the slope north of the motorway and only shows its glass entrance facade.
geology
The Black Mountain is one of the northern edge mountains of the Steigerwald . Its almost horizontal layers of rock belong to the middle Keuper and consist of an upper layer of bubble sandstone up to 50 meters thick , followed by a 30 to 35 meter thick Lehrberg layer. There is reed sandstone underneath . The tunnel tubes run mainly in the Lehrberg layers , which consists of clay and silt stones and in the core area of the mountain has leached material and gypsum is leading. The rock has a relatively low compressive strength and was classified as predominantly usable. The level of the mountain water, which has a high sulphate content, lies above the tunnel tubes.
literature
- Federal Ministry of Transport, Supreme Building Authority in the Bavarian State Ministry of the Interior: Federal motorway A70 . Documentation 2006
Web links
- M. Keuser, S. Schiefer, P. Reichenspurner: New construction of the 2nd tube of the Schwarzer Berg tunnel . Tunnel1 / 2005 (PDF file; 839 kB)
- Image of the west portal of the tunnel
- Image of the east portal of the tunnel (while the construction work for the 2nd tube is still in progress)
