Glossary.
With this excavation procedure the tunnel face is excavated part by part.
Open TBM with excavator or roadheader.
Tunnelling construction method for the creation of underpasses. The pipe arch consists of several pipes, which serve as support structure. This method is employed to construct tunnels with large diameters and short lengths, such as pedestrian subways.
Tunnelling construction method for the creation of pipelines, consisting of individual product or sleeve pipes. With the help of the main jacking station in the launch shaft and, if needed, using intermediate jacking stations, the TBM and the pipeline behind it are advanced up to the reception shaft.
Procedure employed to reduce the skin friction between pipeline and surrounding earth, as well as to support the annulus by means of injected bentonite suspension.
The Pipe Thruster is an additional equipment for horizontal directional drill rigs. It considerably expands the range of application of HDD technology, in particular, with regard to very long crossings and large diameters. The Pipe Thruster is mounted in the launch shaft. While the HDD rig pulls the string of pipes back to the starting point, the Pipe Thruster applies extra force from the other side by pushing the pipeline, which allows for better load distribution on the pipe.
Jacking pipes are lowered separately into the launch shaft and after being jacked with the help of the main jacking station, they form the pipeline.
