Tunnel construction

NATM tunnels

The main goal of geotextiles used in conventional tunnel construction (e.g. acc. NATM) is the protection of the sealing membrane. Furthermor.................................e

Tunnel construction

NATM tunnels | Cut-and-cover tunnels, Galleries

The main goal of geotextiles used in conventional tunnel construction (e.g. acc. NATM) is the protection of the sealing membrane. Furthermore, the drainage function and the long-term resistance to alkaline media have to be considered. TenCate products fulfil all high technical requirements of modern tunnel construction.

Products used:

Protection

TenCate Polyfelt P

TenCate Polyfelt P protection geotextiles are mechanically bonded nonwovens made from UV-stabilized polypropylene. The use of high-quality raw material and continuous stringent internal and external quality controls guarantee a constantly high product quality.

P is the ideal geotextile for protection of geomembranes and other sensitive materials
• P prevents direct contact of angular stones with geomembranes. The combination of geotextile density and thickness reduces stresses caused by the stones which could otherwise damage the membrane.
• P prevents high friction forces developing between gravel and geomembranes on slopes.
• The permeability in the plane of P allows liquids and gases to drain.

P geotextiles protection suitability is derived from the production technology employed
• The production process allows only the use of high quality Polypropylene. This raw material is resistant to all chemical and biological agents usually occurring in soils and building materials. Polypropylene is insoluble in water thus poses no threat to groundwater quality.
• P is specially stabilized against UV radiation to allow prolonged exposure to sunlight.
• Even at low elongation P has relatively high tensile strength. This reduces the risk of slipping failure on slopes and maintains its excellent protection performance.

Cut-and-cover tunnels, Galleries

Cut-and-cover tunnels require special multi-layer lining systems which have to fulfil various requirements. A permanent protection of the sealing membrane is provided by high-quality nonwoven geotextiles. Very often, drainage geocomposites are used which can be easily installed, providing an effective drainage of seepage water even under high surcharge loads.