The hydrofracturing technique is a recent development in the area of stress measurements in rock. Unlike most other methods, it does not measure strain at a point through the use of delicate instrumentation in the test-hole. Rather, it directly determines average stresses over large areas by recording two hydraulic pressures, one necessary to crack open a segment of the test-hole and the other required to keep the fracture open. To do so, it uses simple down-hole mechanical tools so that the method can be employed at any depth from the surface. Elementary elastic relationships exist between recorded pressures and in-situ stresses, and between fracture direction and stress orientation. Our laboratory experiments have confirmed these relationships, and in the last five years we have conducted a number of successful field measurements throughout the United States and elsewhere, at depths between very near the surface and 5000 M. The results of these measurements, details of which are given in the paper, have been used in studying earthquake control problems (rangely, colorado), underground power station design (California, South Carolina), hard rock tunnel design (Wisconsin), and geology and plate tectonics (all the measurements and particularly those in Michigan and Iceland). A general uniformity of maximum principal stress direction throughout the continental United States has been established. Stress magnitudes are affected by regional geologic conditions but generally show linear increases with depth. /Author/TRRL/

  • Availability:
  • Corporate Authors:

    Pergamon Press, Incorporated

    Headington Hill Hall
    Oxford OX30BW,    
  • Authors:
    • HAIMSON, B C
  • Publication Date: 1978-8


  • English

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Filing Info

  • Accession Number: 00189222
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Apr 12 1979 12:00AM