DIAGNOSTIC STRESS-RELIEF CURVES IN STRESS MEASUREMENT BY OVERCORING

The forms of the 'stress-relief curves' (graphs of deformation or strain change due only to stress relief vs overcoring distance relative to measuring sensor position), from data observed during overcoring of a borehole stress measurement device, can be predicted theoretically and are therefore diagnostic of stress relief. These are derived for all sensor orientations in a borehole instrument for a three-dimensional stress field. Comparison of prototype stress-relief curves with those recorded in-situ indicates whether the final observed deformation or strain readings are valid or have been affected by external influences during core formation, leading to incorrect stress analysis. It is, therefore, an important part of the stress measurement process to record sufficient deformation/strain data during the onset of stress relief to enable curves to be drawn. Field stress measurements carried out by the author are given as examples of the correlation obtainable in practice. /Author/TRRL/

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,    
  • Authors:
    • Blackwood, R L
  • Publication Date: 1978-8

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Filing Info

  • Accession Number: 00189184
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Mar 28 1979 12:00AM