THE OPERATIONAL STRENGTH OF FISSURED CLAYS

IN CLAYS THAT ARE GENERALLY, BUT NOT NECESSARILY, STIFF, FISSURES OR JOINTS EXIST WITH VARYING INTENSITY. AS THE SHEAR STRENGTHS ALONG THESE DISCONTINUITIES ARE MUCH LESS THAN THOSE OF THE INTRACT MATERIAL, THEY CONSTITUTE PLANES OF WEAKNESS, WITH THE RESULT THAT THE STRENGTH MEASURED DEPENDS ON THE SIZE OF THE SAMPLE USED. PREVIOUS THEORIES ON THE STRENGTH-SIZE RELATION ARE REVIEWED AND THEIR LIMITATION DISCUSSED. AN EQUATION IS PROPOSED TO DESCRIBE THIS BEHAVIOR AND A METHOD OF DETERMINING THE PARAMETERS INVOLVED IN THE EQUATION IS DEVELOPED. THE RESULTS OF FIELD AND LABORATORY TESTS ON BLOCK SAMPLES OF A STIFF FISSURED CLAY, AND DATA REPORTED IN THE LITERATURE, WERE ANALYZED. IT WAS SHOWN THAT THE STRENGTH-SIZE RELATION MAY BE REPRESENTED ADEQUATELY BY THE PROPOSED EQUATION AND THAT THE STRENGTH OF THE CLAY MASS OPERATIVE IN THE FIELD MAY BE PREDICTED. BY TAKING THE EFFECT OF SAMPLE SIZE, ANISOTROPY, AND TIME TO FAILURE INTO ACCOUNT, THE CONVENTIONAL PHI = 0 ANALYSIS, HITERTO CONSIDERED UNRELIABLE WHEN APPLIED TO FISSURED CLAYS, MAY BE USED FOR SHORT-TERM STABILITY PROBLEMS IF THE UNDRAINED CONDITION IS SATISFIED. /RRL(A)/

  • Availability:
  • Supplemental Notes:
    • Vol 20, No 1, PP 57-74, 15 FIG, 3 TAB, 31 REF
  • Authors:
    • Lo, K Y
  • Publication Date: 1970-3

Media Info

  • Serial:
    • GEOTECHNIQUE
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00234936
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: Nov 8 1971 12:00AM