STANDARD PENETRATION TEST PROCEDURES AND THE EFFECTS IN SANDS OF OVERBURDEN PRESSURE, RELATIVE DENSITY, PARTICLE SIZE, AGEING AND OVERCONSOLIDATION

Granted that good site control is exercised in carrying out the standard penetration test, the energy delivered to the sampler, and therefore the blow count obtained in any given sand deposit at a particular effective overburden pressure, can still vary to a significant extent depending on the method of releasing the hammer, on the type of anvil, and on the length of rods (if less than 10 m). For consistency it is essential to correct the observed blow count N to the value which would have been measured using a specified rod energy. A recommended value, which should be recognized internationally, is 60% of the free-fall energy of the standard hammer weight and drop. The corrected blow count is then designated as N sub 60 and the normalized value (N sub 1)sub 60 at unit effective pressure (1 kg/sq cm or 100 kPa) may be regarded as a basic characteristic of the sand. Factors controlling the rod energy ratio are examined in detail and methods of deriving N sub 60 values are developed.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 425-447
  • Serial:
    • GEOTECHNIQUE
    • Volume: 36
    • Issue Number: 3
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00458553
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 31 1986 12:00AM