Dimpled and drainage sheets for tunnel
construction are often developed for specific
customers and occasionally subject to
extensive quality-assurance processes.
DELTA.-MS 20 and DELTA.-MS are standard drainage sheets for tunnel construction. DELTA.-AT 800 and DELTA.-AT 1200 are specially developed heavy-duty dimpled drainage sheets that are used, for example, in the Gotthard base tunnel.
Dimpled sheets are necessarily perforated by the process of fastening. This, however, is no drawback since it is not the dimpled sheet but the concrete inner shell (if made of waterproof concrete) or an extra layer of plastic sheeting which guarantees water impermeability. The function of the dimpled plastic sheet is to act as a seepage layer and thus relieve the waterproofing by allowing seepage water to drain off without pressure.
For enclosed structures with tubbing segments, Shotcrete: Safety in the mountains, tunnel rehabilitations or cut and cover tunneling, DELTA® offers professional solutions.
© Dörken GmbH & Co. KG · A member of DÖRKENGROUP · DELTA® is a registered trademark of Ewald Dörken AG, Herdecke, Germany.