Döggingen tunnel
The Döggingen tunnel is an approximately 1000 meter long tunnel connection and section of the B 31 in the Schwarzwald-Baar district in southern Baden-Württemberg . Together with the Gauchachtalbrücke Döggingen to the southwest , the tunnel has been bypassing the village of Döggingen since 1999 . Before it was built, the main road ran through the town and, because of the steep inclines, was a critical section on this important east-west connection in the Black Forest .
The tunnel connection consists of the 1170 meter long north tube and the 1002 meter long south tube. Both tubes have two lanes; the south tube is used in two lanes, the north tube initially only as a single lane. Around 800 meters of the tunnel were built using the mining method , 357 meters using the cut-and-cover method. The excavated cross-section is between 99 and 109 square meters or between 118 and 140 square meters in the area of the emergency stop bay. There is a one-sided emergency stop bay for each direction of travel. The two tunnel tubes are connected to each other by three cross passages.
The tunnel was dug by means of mechanical driving using the so-called New Austrian Tunneling Method . The unfavorable soil conditions and the resulting low anchor forces at the west portal made tunnel construction difficult. Permanent anchors had to counteract an incipient landslide.
The first plans for the Döggingen bypass originate from the Third Reich , but were not implemented. A planning draft from 1978 suggested a single-lane crossing of the town in a low-lying position, while local politicians and a citizens' initiative called for the entire tunnel to be covered. The planning approval procedure for the implemented solution began in 1990, and the first construction work began in September 1992. The tunnel was built between 1994 and 1997 and cost around 40.3 million euros. The opening took place on July 23, 2002.
Individual evidence
- ↑ a b Bräunlingen: When the earth swallowed the street , Badische Zeitung, July 28, 2012, accessed on August 5, 2012
Coordinates: 47 ° 53 ′ 44 " N , 8 ° 25 ′ 29" E