LABORATORY AND IN-SITU MEASUREMENTS OF THE DEFORMATION MODULI OF LONDON CLAY

DEFORMATION MODULI OF LONDON CLAY HAVE BEEN DETERMINED FROM IN-SITU LOADING TESTS ON AN 865 MM DIAMETER PLATE IN 900 MM DIAMETER BOREHOLES DOWN TO A DEPTH OF 25 M. THE HIGHEST AND MOST REPRODUCIBLE MODULI WERE OBTAINED FROM TESTS IN WHICH THE LOADING SURFACE WAS CAREFULLY PREPARED BY HAND DIGGING. THE VALUES OBTAINED FROM THESE TESTS WERE SEVERAL TIMES HIGHER THAN THOSE WHICH HAVE BEEN OBTAINED FROM SMALLER IN-SITU PLATE TESTS MADE IN BOREHOLES TOO SMALL TO PERMIT A MAN TO DESCEND AND PREPARE THE BASE OF THE BOREHOLE. VALUES FROM THE 865 MM DIAMETER TESTS WERE MUCH MORE COMPATIBLE WITH THE LARGE-SCALE BEHAVIOR ESTIMATED FROM MOVEMENTS MEASURED ON FOUNDATIONS AND AROUND EXCAVATIONS. THE AVERAGE VALUES OBTAINED FROM THE WELL PREPARED IN-SITU PLATE TESTS WERE 1.8 - 1.8 TIMES THOSE DETERMINED FROM STANDARD TRIAXIAL TESTS ON 38 TO 125 MM DIAMETER SPECIMENS PREPARED FROM SAMPLES WHICH WERE TAKEN USING THE BEST AVAILABLE TECHNIQUES. THE EFFECTS OF DISTURBANCE, REDUCTION IN STRESS DURING EXCAVATION, THE INTERVAL OF TIME BETWEEN EXCAVATION AND TESTING, AND THE SIZE OF THE TESTS ARE CONSIDERED. THE NEED TO STUDY THESE ASPECTS AND TO GIVE ADEQUATE DETAILS ABOUT THE TEST PROCEDURES WHEN QUOTING VALUES OF MODULI IS EMPHASIZED. /AUTHOR/

  • Supplemental Notes:
    • Rept No CP24/73
  • Corporate Authors:

    Building Research Establishment

    Bucknalls Lane, Gorston
    Watford WD2 7JR, Hertfordshire,   England 
  • Authors:
    • Marsland, A
  • Publication Date: 1973-9

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 12 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00236750
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 16 1974 12:00AM