Canopy/umbrella tubes (with diameters of 76-168mm) are a support system used in conventional and mechanical tunnel construction in poor soil conditions.
Common uses
Excavation support or water sealing during tunnel excavation
Process
The drill rig and drill mast are positioned and drilling executed (using the symetrix method) with lost casing (Umbrella tube). Grouting with packer and cement grout is then used if requested.
Advantages
Tubes rearrange loads to improve stability, reduce subsidence and increase work safety in the tunneling area
Tubes can be adapted to enable installation in confined spaces
Different types of pipe joints are available depending on project requirements