Direct Pipe

Direct Pipe® is a combination of the microtunnelling process and the HDD method and was first applied worldwide by SONNTAG. A completely prefabricated steel pipe is laid out behind the pipe press, the so-called Pipe Thruster, over the entire thrust length.

The steel pipe welded to a conventional microtunnelling machine is encompassed by the clamping unit of the Pipe Thruster and pushed into the ground towards the target pit. The supply and disposal lines necessary for the operation of the microtunnelling machine are installed in advance in the prefabricated steel pipe. The proven gyroscope compass system in combination with an electronic hose level ensures precise reaching of the target construction pit.

Advantages over the microtunneling method

The actual driving time is significantly reduced by eliminating the time-consuming coupling processes of individual pipe shots.
In the case of insurmountable obstacles, the tunneling machine along with the pipe string can be completely retracted.

Durchstich Microtunneling Zuerich GP19946 9800px Gerry Pacher

Advantages over the HDD method

The actual product pipe (e.g. gas pipeline) can be pre-pressed directly. The previous driving of a protective pipe is not necessary.
Only the annular gap between the product pipe and the borehole wall is filled with bentonite (in the HDD method, the entire borehole must be filled with bentonite).
A minimum amount of space is required in the area of the target pit.
As a result of the precise advance measurement, the planned route is adhered to with centimeter accuracy.
The excavated tunnel cross-section is permanently supported by the tunneling machine or the product pipe including the