AT – Pipe Umbrella Support System
The System
Basic Concept
The AT – Pipe 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. Besides this standard usage, the system is often applied to increase stability in portal sections and for the re-excavation of collapsed sections in Underground environments. Another application area is ground improvement and waterproofing in combination with all tunnel construction methods.Main Advantages
- Installation with conventional drill jumbos
- Implementation of pipe umbrella drilling with on-site personnel
- Simple and robust system components
- Fast self-drilling installation
- Smallest possible stress relaxation due to an immediate support of the borehole wall during installation
- Accurate installation due to a minimized annular gap
- Length of pipe umbrella pipes can be adapted to confined space
- Different pipe coupling types are available to suit different project requirements
Fields of Application
- Advances in weak ground and ground conditions prone to subsidence
- Advances in fault zones, sediments, or talus
- Portal sections
- Frequently changing ground conditions
- Re-excavation of collapsed drifts or tunnels
- Urban Tunneling
