COMBINED BORED AND DRIVEN PILES USED AT MAIDSTONE

This article gives a brief account of the adaptation of a standard driven cast-in-situ piling technique to combine it with the lined auger boring method, in order to overcome the wet ground conditions on a congested site at Maidstone, Kent. The system used was developed for use where water-bearing granular soils overlie a softer stratum unsuitable for load-bearing and in turn is underlain by water-bearing granular strata which will give a high carrying capacity using a pile with an enlarged base. The dense upper granular layer is prebored using a rotary auger and a lining casing sunk with the aid of a vibrator through the dense strata. The material inside the casing is removed with the auger rig and preboring continued to about 600mm above the water-bearing granular stratum. A piling rig is used to pitch a steel piling tube in the hole, the bottom being closed to prevent soft material contaminating the driving plug of concrete placed at the base of the tube. A drop hammer drives plug and tube to the required depth. The plug is then expelled and an enlarged base formed by forcing successive charges of concrete into the surrounding stratum by means of a drop hammer. Details are given of the maidstone contract including the equipment used. /TRRL/

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Publication Date: 1974-11

Media Info

  • Features: Photos;
  • Pagination: p. 48-49
  • Serial:
    • GROUND ENGINEERING
    • Volume: 7
    • Issue Number: 6
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00098131
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 18 2001 12:00AM