Applications: Car tunnels, Train tunnels, Underwater tunnels

Dorken DELTA Dimpled Sheeting
DELTA dimpled sheeting is manufactured from environmentally friendly, long-lasting, and resistant special polyethylene. It provides a highly effective and efficient seepage and drainage layer in all areas of construction. It is pressure resistant, rotproof, and resistant to saline solutions, inorganic acids, alkalis, and liquids such as alcohols, organic acids, esters, ketones and similar substances. DELTA dimpled sheeting cannot be damaged or affected either by minerals, humic acid, or bacterial decomposition in the earth nor can bacteria, fungi and micro-organisms attack it. In regard to both the soil and the groundwater, the dimpled sheeting remains completely inert and does not give off any damaging or environmentally hazardous substances. In the laying of DELTA dimpled sheeting any health risk can be completely excluded. Different stud heights make sure that water can drain away properly in horizontal or vertical seepage layers. A filter fabric prevents ground particles from floating into the drainage layer. A thermic-welded layer allows dimpled sheeting to be used as the base for shotcrete or mortar.

Tunnelling – Unobstructed flow path for water
In tunnelling, it is essential to provide adequate water drainage both during and after the construction phase. Depending on the prevailing mountain and water conditions, both the upper part of the tunnel arch and the tunnel base are affected by fissure, stratum, and seepage water. The long-term stability and permanent usability of a tunnel depend on whether the inner shell and base are reliably protected against water ingress and consequent frost damage. It is imperative to collect the surface and seepage water over a wide area between the inner and the outer shell of the tunnel, both in the upper and in the lower parts of the tunnel, and to remove it through carefully designed drainage and seepage layers. This applies particularly for efficient tunnelling methods using water impermeable concrete which must not come into contact with seepage water during the curing process nor be loaded hydrostatically. The various DELTA dimpled sheetings offer rational and dependable solutions for coping with water in all kinds of tunnel construction projects according to the existing mountain and water conditions. While the studs pointing outwards, that is against the ground or rock or a stabilizing and filtering shotcrete layer, a complete conduit system is provided by the spaces between the studs allowing the water to flow unimpeded to the drainage system. From the very start, water is prevented from building up against the waterproofing layer which can be fixed directly to the dimpled sheeting by appropriate fixing means. When water impervious concrete is used, DELTA dimpled sheeting serves as a permanent formwork. The seepage water is held back during the curing phase.

  1. Water influx through fissures
  2. Bedrock
  3. Shotcrete
  4. Delta PT dimpled sheeting
  5. Drainage pipe
  6. Tunnel tube – shotcrete
  7. Reinforcement mesh
  8. Concrete lining