The Rosenstein Tunnel in Stuttgart, Germany, is part of a road construction project that will close a gap in the development of the B 10 Federal Road between the town of Zuffenhausen and Stuttgart East. Thanks to the construction of the tunnel, Prague Street can be reduced from four to two lanes. This will significantly reduce traffic congestion in the affected districts and allow the creation of new green space.
With a total length of approx. 1,300 m, the new road tunnel passes below Rosenstein Park and parts of the Wilhelma Zoological and Botanical Gardens. After tunnel completion, which is scheduled for 2020, traffic will be run through both tunnel tubes on two lanes in each direction.
At its deepest point, the tunnel is located 20 m beneath Rosenstein Park. For 750 m from the Neckar River in the direction of Prague Street, the two tunnel tubes are advanced using the underground method. The tunnel is accessed via an about 40 m long approach adit. By using the underground method, interferences with Rosenstein Park and Wilhelma Zoo can be avoided. The open cut method is only used for the areas that will connect the tunnel to Prague and Neckartal Streets.
Excavation is up to 18 m deep
The excavation at Prague Street accommodates both tunnel tubes as well as the new operational building and was therefore excavated to a depth of up to 18 m. To stabilize this excavation, DSI supplied 532 temporary strand anchors with a total length of 9,110 m. The strand anchors were installed in the excavation walls in lengths of 10 to 22 m. Furthermore, 566 bar anchors with a total length of 4,367 m were used. The bar anchors were installed in individual lengths from 2 to 14 m.