Guidelines in the selection and use of extensometers are set out. The extensometer consists of one or more reference anchors at various depths in a borehole and a reference head at the borehole collar. By mechanical or electrical means the relative displacements of the rock, generally as transmitted to the rods or wires connecting the anchors with the reference head, are measured. Typical components of a borehole extensometer are described, in particular displacement sensors, anchors, rods and wires. Performance requirements are given for four ranges of precision corresponding to the order of magnitude of displacements that have engineering significance for the varying applications, from in situ rock testing to monitoring large moving landslides. Typical applications are discussed. Procedure, calculations and data processing are described. The details required in reporting results are listed. /TRRL/

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,    
  • Publication Date: 1978-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00195454
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Sep 15 1979 12:00AM