Self Drilling Anchor Umbrella System is a pre-support measure used in weak ground conditions in conventional as well as mechanized Tunneling. Pipe umbrella pipes increase the stability in the working area by transferring loads in the longitudinal direction and decrease excavation induced deformations. The system increases safety in the working area.
Beside this standard usage, the system is often applied to increase stability in portal sections and for the re-excavation of collapsed sections in underground construction. Another application area is ground improvement and waterproofing in combination with all tunnel construction methods.
Fields of Application
• Advances in weak ground and ground conditions prone to subsidence
• Advances in sediments or talus
• Re-excavation of collapsed drifts or tunnels
• Advances in frequently changing ground conditions
• Advances in alpine fault zones
• Portal sections
• Urban Tunneling
Main Advantages
• Execution of pipe umbrella drilling with on-site personnel
• Accurate installation due to a minimized annular gap
• Length of pipe umbrella pipes can be adapted to constricted space
• Different pipe coupling types available to suit different project requirements
• Smallest possible stress relaxation due to an immediate support of the borehole wall during installation
• Installation with conventional drill jumbos
• Simple and robust system components
• Fast self-drilling installation