INHERENT ANISOTROPY IN A SAND

PRESENT KNOWLEDGE OF INHERENT ANISOTROPY IS REVIEWED AND THE DEVELOPMENT OF A CUBICAL TRIAXIAL CELL FOR STUDYING THE INHERENT ANISOTROPY OF NON-COHESIVE GRANULAR MATERIALS IS DESCRIBED. THIS APPARATUS IS UNUSUAL AS IT OFFERS POTENTIAL INDEPENDENT CONTROL OF THE THREE PRINCIPAL STRESSES THROUGH FLEXIBLE STRESS CONTROLLED BOUNDARIES, AND SOME DISCUSSION OF THE RELATIVE MERITS OF DIFFERENT TYPES OF TRUE TRIAXIAL CELLS IS OFFERED. UNIFORM LOCAL STRAIN DISTRIBUTIONS WERE MEASURED RADIOGRAPHICALLY AND FAVORABLE COMPARISONS WERE MADE WITH SHEAR BOX CONVENTIONAL TRIAXIAL RESULTS. SAMPLES WERE PREPARED IN A TILTING MOULD TO GIVE DIFFERENT DIRECTIONS OF SAMPLE DEPOSITION WITH RESPECT TO THE SAMPLE AXES AND APPLIED PRINCIPAL STRESS DIRECTIONS. IT WAS FOUND THAT THE INHERENT GEOMETRIC ANISOTROPY PRODUCED IN SAMPLES BY POURING THROUGH AIR IN ONE DIRECTION CORRESPONDED TO A STRENGTH AND PRE-FAILURE STRESS-STRAIN ANISOTROPY. FOR THE ROUNDED LEIGHTON BUZZARD SAND TESTED IN DRAINED TRIAXIAL COMPRESSION, ROTATING THE DIRECTIONS OF POURING THROUGH 90 DEGREES, RELATIVE TO THE PRINCIPAL STRESS AXES, RESULTED IN A CHANGE IN STRESS RATIO AT FAILURE OF 10% FOR THE SAME POROSITY. DIFFERENCES OF WELL OVER 200% IN THE AXIAL STRAINS TAKEN TO REACH A GIVEN PRE-FAILURE STRESS RATIO WERE DEMONSTRATED. COINCIDENCE BETWEEN THE PRINCIPAL AXES OF STRESS AND STRAIN INCREMENT WAS SHOWN WHILE THESE ANISOTROPIC EFFECTS WERE OCCURRING. /AUTHOR/

Language

  • English

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 115-28
  • Serial:
    • GEOTECHNIQUE
    • Volume: 22
    • Issue Number: 1
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00236999
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: May 29 1973 12:00AM