MICROFRACTURING AND THE INELASTIC DEFORMATION OF ROCKS IN COMPRESSION

CRACKING DURING DEFORMATION OF ROCKS IN COMPRESSION WAS STUDIED BY DETECTING AND ANALYZING RADIATED ELASTIC WAVES, USING A HIGHLY SENSITIVE NEW EXPERIMENTAL METHOD. THE PATTERN OF CRACK OCCURRENCE FOR A WIDE VARIETY OF ROCKS, AT CONFINING PRESSURES UP TO 5 KB, WAS CLOSELY RELATED TO STRESS-STRAIN BEHAVIOR. DILATANCY IN THE REGION ABOVE HALF THE FRACTURE STRESS WAS DIRECTLY PROPORTIONAL TO CRACKING. MICROFRACTURING OF BRITTLE ROCK WAS COMPARED WITH THAT OBSERVED IN FRICTIONAL SLIDING AND IN DEFORMATION OF DUCTILE ROCK. CATACLASTIC DEFORMATION OF MARBLE WAS SIMILAR TO FRICTIONAL SLIDING BUT DISTINCTLY DIFFERENT FROM BRITTLE DEFORMATION AND WITH INCREASING PRESSURE (TO 4 KB) THE MARBLE UNDERWENT A GRADUAL TRANSITION FROM CATACLASTIC TO FULLY PLASTIC FLOW. A MODEL OF DEFORMATION IN INHOMOGENEOUS BRITTLE MATERIAL IS PROPOSED WHICH PREDICTS THE OBSERVED MICROFRACTURING ACTIVITY AND INELASTIC STRESS-STRAIN BEHAVIOR OF ROCKS. ACCORDING TO THIS MODEL, MICROFRACTURING EVENTS IN THE DILATANT REGION BELOW 95 PERCENT OF THE FRACTURE STRESS ARE RANDOMLY INDEPENDENT, BUT AT HIGHER STRESSES THEY ARE NOT INDEPENDENT AND ARE CORRELATED WITH THE FORMATION OF THE FAULT. /AUTHOR/

  • Supplemental Notes:
    • Vol 73, No 4, PP 1417-1432
  • Authors:
    • Scholz, C H
  • Publication Date: 1968

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  • Accession Number: 00235369
  • Record Type: Publication
  • Source Agency: Geophysical Abstracts
  • Files: TRIS
  • Created Date: Oct 14 1994 12:00AM