Cavidrain® Liner

Usage & Purpose

• Simplified tunnel lining system
• Materials & labour cost reduction
• Reduced installation requirements
• Improved drainage capacity
• Minimised damage caused by mineral calcification

Application

• New tunnel construction
• Repair of existing tunnels
• Highway tunnels
• Railway tunnels
• NATM constructed tunnels
• Drill and blast tunnels
• Metro underground stations
• Cable tunnels
• TBM tunnels

General Information

Cavidrain® Liner is a combined drainage and waterproofing liner that is welded to form an integral waterproof system. The sheets are easily fixed to the smoothed excavated walls with a sealed fixing detail and the system is finished with shotcrete.

Product Information

Traditional methods of groundwater exclusion are difficult to install with any degree of reliability in modern tunnel constructions. Cavidrain® Liner provides a drainage layer that collects infiltration water from the excavated tunnel face, while also acting as the waterproofing function.

In typical installations, Cavidrain® Liner is fixed to the smoothed, excavated face of the tunnel with rondels and covered with shotcrete. Shotcrete can be sprayed directly to Cavidrain® Liner to create the surface finish, offering 20% less rebound loss than a smooth PVC liner.

Cavidrain® Liner being LLDPE is highly flexible and acts to minimise the build-up of hydrostatic pressure, thus protecting and enhancing the integrity of the tunnel.