delta_technical_20pp_brachbach_tunnel

Brachbach tunnel:
The tunnel was renovated with a double layer of shotcrete. DELTA®-PT conducts away water between the inner and outer lining, and serves as the base for the reinforced inner shotcrete lining.

delta_technical_20pp_euro-tunnel

Euro-Tunnel:
In the pressure-relief embranchments, dimpled sheeting mechanically fixed against the rock ensures a proper drainage of seepage or pressurized water. A shuttering made from water impermeable concrete was directly installed against the dimpled sheeting. In the area of the connection tunnels a geotextile was applied onto the dimpled sheeting and above it waterproofed with PVC-sheets.

delta_technical_20pp_london_underground

London Underground:
Delta-PT has been used extensively for many years as part of London Underground's station refurbishment plans.
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. With 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 permanent formwork. The seepage water is held back during the curing phase.
delta_technical_20pp_föhrlibuck_tunnel
Föhrlibuck tunnel 1986:
Tunnelling is by the open-cast method. To remove the surface and seepage water, 6000 m2 of DELTAS-DRAIN were used to cover the entire external surface of the tunnel arch. The tunnel was then covered with excavated material (150,000 tons) to a depth of 2.0 to 3.5 m.
  
Tunnel renovation
Water damage to old types of tunnels can be eliminated frequently only by installing a drainage system. By lining the tunnel vault with DELTA-PT, a dimpled sheeting with an integral plastering layer, a hollow space is created which drains away the fissure and stratum water. The thermic-welded plastic mesh holds the shotcrete during application.

delta_technical_20pp_london_underground_delta-pt