NON-DESTRUCTIVE INTEGRITY TESTING OF BORED PILES BY GAMMA RAY SCATTERING

The method of testing bored concrete piles to locate possible faulty zones by gamma ray backscattering is described. This technique, responsive to a void with a weak source, was chosen by the authors as more desirable for study than other radiation methods as it is sensitive to clay or sand inclusion and does not require inconvenient safety measures. The equipment developed consists of a probe 48 mm in diameter and 600 mm long, attached by means of a 30 m long cable to a counting system. To perform a test the probe is lowered into a tube in the foundation and the result registered on a counter or chart. Intensity of radiation at the detector, which is the detected rate of count in units of counts per second, depends on the mass per unit volume of material surrounding the probe. For 90 piles, correlative information was available from coring or from excavating to expose the pile. In 76 of these cases there was agreement between the gamma ray method and these results; in 14 cases the test method discovered faulats not located by coring.

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • Preiss, K
    • Caiserman, A
  • Publication Date: 1975-5

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 44-46
  • Serial:
    • GROUND ENGINEERING
    • Volume: 8
    • Issue Number: 3
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00098599
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1975 12:00AM