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JACKED SOLID CONCRETE PILE
(vibration free, displacement pile)

The jacked solid concrete pile is built up of concrete pile sections which are pressed into the ground by means of a hydraulic system. The pile is used for underpinning and for providing additional bearing capacity (partial underpinning). The building which is underpinned together with a new concrete floor provides the required reaction for jacking in the piles. Anchors are concreted into this concrete floor and holes are left open through which the piles are pressed. The pile is jacked into the bearing stratum with a force 1.7 to 2 times the required bearing capacity. If screw spliced pile sections are used, the jacked solid concrete pile can be provided with an enlarged base. The working method is vibration free.

Since light, dismountable machines are used, this system is extremely well suited for working under difficult conditions and in very confined working spaces. The drawing given above gives an indication of how this method works. By using this method it is possible to concrete the piles into the concrete structure at a preload.

The minimum working height is 0.8 m. As a result it is possible to press a jacked solid concrete pile under an existing foundation. This existing foundation is then used as the counterweight for jacking the pile.



APPLICATIONS OF JACKED SOLID CONCRETE PILES:
  • for underpinning foundations;
  • when a large counterweight is available;
  • when work has to be carried out vibration free, such as underpinning the foundations of an unstable structure, near foundation piles which are in use or in the vicinity of equipment sensitive to vibrations;
  • when the working height is very limited; a solid concrete jacked pile can for example be placed under existing foundations, in which case the foundations themselves are used as the counterweight;
  • in places which are difficult to reach, for example a cellar or basement; the equipment required can be brought through a very small opening;
  • where work has to be carried out at low noise levels;
  • it is possible to work without welding and without use of combustion engines (at danger of explosion).
  • diverse Einsatzmö glichkeiten dieser Technik auf zugehörigen Gebieten, u.a.:



TECHNICAL INFORMATION ON JACKED SOLID CONCRETE PILES:

  • Concrete pile sections:
    Diameter 280 mm, 310 mm, 350 mm;
    Length of concrete pile sections 1 m, 1.75 m, 2 m;
    Grade of concrete: C30/37;
  • Diameter of pile base: a base with a diameter of 470 mm is only possible with a shaft diameter of 280 mm;
  • Length of pile: depends on the soil conditions;
  • Pile tip level and allowable bearing capacity: depends on the available reaction; only in accordance with advice based on considerable experience with this system;
  • Rake: n/a;
  • Required reaction: in accordance with the specifications;
  • Minimum working height: 0.8 m, with a minimum access width of 0.4 m;
  • Monitoring and testing:
    The pile is pretested with a force 1.7 to 2 times the required bearing capacity.

Subject to alteration

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