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DYWIDAG Strand Anchors Stabilize Baden-Wuerttemberg’s Largest Road Construction Project, Deutschland

DYWIDAG Strand Anchors Stabilize Baden-Wuerttemberg’s Largest Road Construction Project

In the spring of 2008, construction started on a project that is considered the largest and most expensive road construction project of the federal state of Baden-Wuerttemberg, Germany: The 4.1km long ring road around Schwaebisch Gmuend near Stuttgart that has a total cost of approx. 230 Million Euros.

For many years, the B29 federal road, which runs through Schwaebisch Gmuend’s center and is an important connection between Stuttgart and the A7 Motorway near Aalen, has been a traffic bottleneck. The 35,000 vehicles per day using this road cause regular traffic jams and are a continuous nuisance to residents. The new B29 bypass will be located underneath the town for a total length of 2,230m. The tunnel itself is partly constructed by mining techniques and partly by the open cut method. The tunnel tubes are built in three layers from top to bottom.

The western part of the section is being constructed as an impermeable trough structure with a base slab that is up to 2.80m thick. The watertight pit lining is a tied back contiguous bored pile wall, the foundation of which is supported by large bored piles. An open cut tunnel structure is connected to this trough structure.

Construction work in the eastern section was particularly complicated due to the proximity of the Rems river.

Before excavation water could be discharged into the river, it had to be processed in a treatment plant specifically set up for this purpose. In addition, retaining walls were necessary to stabilize the Rems.

DSI supplied 1,362 DYWIDAG Strand Anchors for stabilizing the excavations; 113 of these anchors were Permanent DYWIDAG Strand Anchors with 4, 5 or 7 strands each. Additionally, 1,249 Temporary DYWIDAG Strand Anchors with extended service life and 2 to 7 strands each were used for this project. These semi-permanent anchors were especially developed for an extended temporary service life of up to 4 years. In contrast to Permanent Strand Anchors with double corrosion protection (DCP), those parts of the temporary anchor which are exposed to corrosion are modified to suit higher service life demands.

Completion of the ring road is planned for 2012 – in time to prepare the grounds for Baden-Wuerttemberg’s Garden Festival, which will be held in Schwaebisch Gmuend in 2014.