Construction Equipment

Safe Securing of the Excavation with Spraying Head Kinematics

With 2 highly moveable wet sprayed concrete manipulators a Joint Venture is securing the tunnel section of the bypass B 29 in Schwäbisch Gmünd. As the tunnel will be located below the underground water level once it is completed, a tight shotcrete shell with as uniform a surface as possible is essential. The special spraying head kinematics for the 2 applied concrete wet spraying machines provides the best possible prerequisites towards this end.

The altogether 2,530  m long construction project is being set up by the Tunnel Schwäbisch Gmünd JV (consisting of Züblin, Baresel, Hinteregger, ÖSTU-Stettin). The tunnel is split up from west to east into a trough section (215  m – previously constructed as a separate contract section), an open section built by cut-and-cover (230  m) and the central tunnel driven by mining means (1,687  m). In the east it is connected to a 315  m long tunnel section produced by cut-and-cover with an adjoining trough section (90  m) (Fig.1).

During an initial development phase the structure will be operated as...