Zakládání staveb, Inc., in Baden-Wuerttemberg that is share on a special foundation work on an extensive project of the urban tunnel in Karlsruhe

In Karlsruhe, situated in southwestern Germany near the French border, there is currently arised a large transport project of the so-called urban tunnel. Its purpose is to seduce all rail transport, both tram and the train into the tunnel that will pass under the two major streets with a total length of about 3 km. Society Zakládání staveb on this project for more than 600 mil. Euro participates in special foundation technologies from December 2013 to the present day (2016). It was the technology of diaphragm walls, jet grouting, the classic ground strand anchors and the so-called GEWI bars.

The whole construction of urban tunnel is divided into two T-shaped main sections and is built in the city center under the city's largest streets: in the east - west under Street Kaiserstrasse length of 2.4 km and a north - south under Karl-Friedrich Strasse in the length of about 1 km. In the east - west direction a tunnel is completely driven by TBM, on a perpendicular branch with a length of 250 m will be driven by NATM in air pressure, the remaining part is excavated. Individual sections are further divided on the exit ramps, tram stops and stretches between them.

Thanks to the local geological conditions and the absence of impermeable bedrock must be separate building units completely sealed against water. The basic design concept of the individual sections of the construction lies in making cladding of underground walls (PS) or sheet piles, anchored at several levels by strand ground anchors. The bottom of the excavation pit is sealed with jet grouting (TI), which simultaneously expands the heels of claddings. Shallow deposited layers of sealing TI is further reinforced by tension GEWI rods against groundwater buoyancy.