Manned pipe jacking with open controllable shield for pipes DN 900 to DN 2400

Pipe jacking is carried out via soil excavation directly in the control head at the working face - manually or using a draw hoe. It is controlled via hydraulic jacks. Both the horizontal and vertical axes are measured using a laser from the starting excavation pit. Soil excavation directly at the face means that obstacles can also be removed during tunnelling. There is no risk of having to create a recovery pit or abandon the drive. Even boulders can be recovered or split to a transportable size and removed from the pipe string. In order to minimize the frictional forces generated during the tunnelling work, the entire pipe string is lubricated from the inside with a bentonite suspension. Depending on the ground conditions and the length of the drive, expansion stations can also be installed, making lengths of up to 150 m possible.

Depending on the water level, any groundwater or stratum water that occurs is lowered via a groundwater lowering system with filter pipes and a vacuum system. At low water levels, the dewatering is operated from the control head with a drainage system and submersible pump.
All commercially available pipes made of reinforced concrete, GRP, steel and polymer concrete can be used as jacking pipes.

The quality assurance for sewer construction in accordance with RAL-GZ 961 is carried out in accordance with the requirements of assessment group VO. This includes the trenchless manned laying and testing of wastewater pipes and sewers with open controllable shields without compressed air or manned laying and testing using the mining method.