SCALE EFFECTS IN ROCK STRESS MEASUREMENTS . PROCEEDINGS OF THE FIRST INTERNATIONAL WORKSHOP ON SCALE EFFECTS IN ROCK MASSES, LOEN, NORWAY, JUNE 7-8 1990

This paper is an attempt to review several aspects of the effect of scale on stress measurements in the earth's crust. This is not meant to be comprehensive, and therefore some important facets of the scale effect have been left out. Several categories of scale effects are discussed. One type of scale effect is inherent in the rock parameters used to interpret field measurements, such as the tensile and compressive strengths of the rock. A second scale effect is related to the volume of rock over which the principal stresses are determined. Here is where overcoring methods using strain gages fundamentally differ from hydraulic fracturing which averages stress over an area equal to the induced fracture size. A third type of scale is the lateral extent over which localized stress measurements dominate. A fourth scale is the depth range over which a stress measurement or a series of such tests can be considered to be representative. Examples in the form of experimental results and field case histories are given for each type of scale effect, and comparisons between different methods are also provided. Questions are raised about both the lateral and the vertical extent over which a limited set of stress measurements can be considered valid, and a warning is given against the use of rough regional stress characteristics to substitute for local measurements in major projects. (Author/TRRL)

  • Availability:
  • Corporate Authors:

    AA Balkema

    P.O. Box 1675
    Rotterdam,   Netherlands  BR-3000
  • Authors:
    • HAIMSON, B C
  • Publication Date: 1990

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00609528
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • ISBN: 90-6191-660-7
  • Files: ITRD, TRIS
  • Created Date: Jun 30 1991 12:00AM