Official opening of the Kreuzstraße Tunnel in Tuttlingen
On 17.02.2011, the official opening of the Kreuzstraße urban tunnel took place in Tuttlingen. An introductory address by Mr. Hans-Joachim Bumann, the head of the department for roads and traffic of the Freiburg regional council, was followed by speeches by Dr. Peter Ramsauer, the Federal Minister for Transport, Building and Urban Development and by the Minister for the Environment, Nature Conservation and Transport in the state of Baden-Württemberg, Ms. Tanja Gönner.
On 17.02.2011, the official opening of the Kreuzstraße urban tunnel took place in Tuttlingen. An introductory address by Mr. Hans-Joachim Bumann, the head of the department for roads and traffic of the Freiburg regional council, was followed by speeches by Dr. Peter Ramsauer, the Federal Minister for Transport, Building and Urban Development and by the Minister for the Environment, Nature Conservation and Transport in the state of Baden-Württemberg, Ms. Tanja Gönner.
The Minister underlined the importance of this major inner-city project for the entire region. She pointed out the improvements to safety for road users and the enhanced quality of life and housing for local residents. At the same time, she emphasized the fact that “the tunnel will sustainably reduce the amount of traffic passing through the center of Tuttlingen”.
The idea of building the tunnel was born in 1979 and the first planning steps took place in 1983. The public planning procedure started in 1989, the year that the Berlin Wall fell, and construction started in the autumn of 2007. The costs for the tunnel amounted to around 31 million Euros.
To improve the traffic situation in Tuttlingen and to create an efficient inter-regional road network, two major roads, B 311 and B 14 were integrated. The resulting road now leads underground through a 948 m long tunnel. Its first section has a closed reinforced concrete frame; after this, the reinforced concrete frame is open. There are several emergency exits which were also constructed in reinforced concrete and connected with the tunnel.
Many temporary structures like construction pits, temporary bridges and supporting frameworks were required during the realization of the project. In the first section, the construction pit shoring was realized as a twice-stiffened contiguous bored pile wall and in the remaining section as a once-stiffened non-continuous bored pile wall.
The checking engineer for this project is Dr.-Ing. Ioannis Retzepis.
Construction pit data: 1.700 bored piles, 145.000 m3 of earth excavated, 20.000 m2 of shotcrete, 7.100 m of steel girders.
Data on the shell of the structure: 4.300 t of reinforcement steel, 10.600 m2 of fire protection reinforcement, 27.000 m3 of concrete.
