Pipe jacking
The pipe jacking is a method for grave laying of pipes.
Reinforced concrete pipes with a length of three or four meters are usually used for this.
The overall length can of course be varied and the tunneling route can be designed to the centimeter.
The jacking systems were specialized for the installation of reinforced concrete pipes, steel jacking pipes are only used in exceptional cases. The advantage is that there is no need to weld the individual pipes, as the concrete pipes have an integrated sealing system.
Procedure
Machines are usually used to excavate the entire face. These full-face machines usually convey the material to the outside via a bentonite suspension, where it is separated again and ejected via a separation system. With this method, groundwater and almost all soil conditions from cohesive soil to rock can be controlled.
Another method is the partial cutting method with partial excavation of the face. For example, a machine with an excavator arm or a cutting device can be used here. The excavated material is transported to the outside via a conveyor belt and a chute. The advantage of this method is that the face is accessible in the event that known obstacles have to be removed by hand.
With the dynamic ramming process, pipes up to 4 meters in diameter can be installed in lengths of well over 100 m under roads, rail tracks, rivers and the like. to be driven forward. The rams used for this have a cylindrical design with a conical head. Ramming cones or connecting cones create the non-positive connection to the jacking pipe. The piston in the machine housing is accelerated with compressed air from one or more construction site compressors, and the pipe to be driven is applied via the connecting cone.
The extreme stresses that arise during use due to the high impact energy of up to 40,000 Nm require one-piece, thick-walled machine housing.
With the advance, the soil gradually penetrates the pipe. The pipe is emptied after the advance with water and compressed air or, depending on the pipe size, manually or mechanically.
scope of application
The pipe jacking is used z. B .:
- when crossing traffic routes (tracks, roads, rivers)
- in pipeline construction
- in the manufacture of pipe umbrellas in tunnel construction and underpasses up to 4 m in diameter
- for vertical use z. B. Foundations
- when Abrammen of piles
- when moving trees for the production of root baskets
literature
- Dietrich Stein: Trenchless line construction . Ernst & Sohn , Berlin 2003, ISBN 3-433-01778-6 ( limited preview in the Google book search).
- Max Scherle: Pipe jacking volume 1, technology, machines, devices. 2nd Edition. Bauverlag, Wiesbaden 1986, ISBN 3-7625-0595-0 . (First edition 1977)
- Max Scherle: Pipe jacking volume 1, statics, planning, execution. Bauverlag Wiesbaden 1977, ISBN 3-7625-0773-2 .
- Max Scherle: Pipe jacking volume 3, calculation examples, comment. Bauverlag, Wiesbaden 1984, ISBN 3-7625-2009-7 .
- Hermann Schad, Tobias Bräutigam, Steffen Bramm: Pipe jacking: Pressing accessible lines. 2nd Edition. Ernst, Berlin 2008, ISBN 978-3-433-02912-1 .
- German Association for Water Management, Sewage and Waste e. V. (Ed.): Pipe jacking and related processes . DWA worksheet (= DWA set of rules . A 125). DWA, Hennef 2008, ISBN 978-3-941089-30-3 (English: Pipe Jacking and Related Techniques: Standard . Translated by Tanja Herzberg).