Precise guided boring with the TERRA-JACK 200

Challenging 30-meter pipe jacking

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A construction project in Germany required the installation of an HDPE water pipeline over a distance of 30 meters. The TERRA-JACK 200 steerable guided boring system was successfully deployed for this task. The new HDPE water pipeline had to be installed through challenging, hard ground over a distance of approximately 30 meters. A starting pit and a target pit were excavated for the work. Due to local conditions and to secure the work area, appropriate shoring was used in the starting pit. The shoring is designed to allow pipes and pulling accessories to be fed directly into the pit. The guided boring system was positioned in the starting pit, and the jacking process was carried out toward the target pit. The hard ground presented a particular challenge. The TERRA-JACK 200 is equipped with 14 tons of thrust for the pilot bore and 20 tons of pulling force for the backreaming process. It is powered by a gasoline power pack or the hydraulics of a mini-excavator (40 l/min at 235 bar). Under such conditions, controlled guidance of the boring head and continuous monitoring of the bore path are crucial to maintaining the specified route as precisely as possible.

Precise tracking with Underground Magnetics

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In the first step, the TERRA-JACK 200 was used to perform a steerable pilot bore. The Mag X Geo tracking system from Underground Magnetics was used to determine the position, roll angle, and depth. This allowed the machine operator to monitor the progress of the pilot bore and make targeted corrections as needed. After approximately 30 meters, the pilot bore reached the target pit as planned.

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Backreaming process

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Subsequently, the backreaming process was prepared for the installation of the new HDPE water pipeline. During backreaming, a front-mounted reaming star was used to loosen the ground ahead of the reaming cone. The water pipeline was successfully installed in a very short time using the TERRA-JACK 200. The project demonstrates the advantages of compact guided boring technology, especially for shorter, high-precision pipeline installations. Despite the challenging ground conditions, the connection between the starting and target pits was established trenchlessly with minimal surface disruption.