A COMPARATIVE FIELD STUDY OF ROCK STRESS DETERMINATION TECHNIQUES.

Abstract

Numerous different techniques have been developed for the determination of in-situ stresses in rocks. Generally, each system has been designed and calibrated or tested independently of the others. The purpose of this research was to make a comparative study of several different techniques under the same carefully controlled field conditions. A four foot square on a quarry floor was first instrumented and then relieved from any regional stresses by drilling four slots (4 ft. 6 in. long and 9 ft. deep) at right angles around the instrumented region. The piece of rock isolated by this way was then restressed by means of flat jacks inserted in the slots. With this arrangement it was possible to compare the various techniques of rock stress determination in either uniaxial or biaxial stressfields generated by pressurizing the opposite pairs of flat jacks. Results strongly suggest that data obtained from current techniques of stress determination cannot be relied upon within plus or minus 20% to 30% of the mean values, even under carefully controlled conditions. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1969
Accession Number
AD0686307

Entities

People

  • Francois Bonnechere

Organizations

  • University of Minnesota

Tags

DTIC Thesaurus Topics

  • Field Conditions
  • Mechanics
  • Right Angles
  • Rock Mechanics

Readers

  • Geotechnical Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Systems Analysis and Design