The author discusses the factors that should be taken into account when the final depth of driven piles is determined. He points out that the formula in general use do not take into account differences between hammers or the type and depth of the soil being penetrated. He first discusses the influence of hammer type, stating that hammers delivering frequent lighter blows (approaching a vibratory action) are most effective in sands and gravels, whereas those delivering slower heavier blows (approaching a jacking action) are better in stiff clays. He contracts different types of driver (steam or air operated, diesel and drop hammer types) and the differences between top-and base-drive systems. He then disucsses subsoil influence and makes particular reference the effect of the displacement that occurs in loose to medium compacted sands and gravels. Here the density of the piles can be a major factor in determining resistance sets and pile lengths, and the results obtained with isolated trial piles can be very different from later results. He also refers to driving in sensitive clays and chalk which can have the effect of producing excessive programmes of work unless the effects of the material are taken into account. He concludes that, in piling it is for the engineer to use the pile-driving formula as one tool in fashioning a pile design, and not for the engineer to be used by the formula. /TRRL/

  • Availability:
  • Corporate Authors:

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 
  • Publication Date: 1974-3-7

Media Info

  • Features: Photos;
  • Pagination: p. 34-35
  • Serial:
    • Volume: 257
    • Issue Number: 7931
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00260320
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 22 1974 12:00AM