MORPHOLOGICAL AND MECHANICAL ANISOTROPY OF A RECENT BEACH SAND

ORIENTED, UNDISTURBED SPECIMENS OF A RECENT BEACH SAND FROM PORTSEA, VICTORIA, HAVE BEEN LOADED AND FAILED IN A STANDARD TRIAXIAL TESTING MACHINE, TO STUDY THE RELATIONSHIP BETWEEN THE MORPHOLOGICAL FABRIC OF THE SAND AND ITS MECHANICAL REACTIONS. THE SAMPLING SITE IS REPRESENTATIVE OF SIMILAR SITES IN MANY OTHER PARTS OF THE WORLD. THE MORPHOLOGICAL FABRIC HAS A MONOCLINIC SYMMETRY, I.E., A SINGLE VERTICAL SYMMETRY PLANE PERPENDICULAR TO THE COASTLINE. THIS IS IN STRONG CONTRAST TO THE CURRENT IDEA OF GRAVITATIONALLY CONTROLLED COMPACTION AND CONSOLIDATION LEADING TO 'CROSS-ANISOTROPY'. THE FAILURE PLANES DEVELOPED DURING TESTING ALSO OBEY THE SAME MONOCLINIC SYMMETRY ARRANGEMENTS. A COMPARISON OF THE SECANT MODULUS VALUES SHOWS A SIGNIFICANT DIFFERENCE BETWEEN VERTICALLY AND HORIZONTALLY ORIENTED TEST CYLINDERS. DIFFERENCES IN THE SECANT MODULUS FOR VARIOUS ORIENTATIONS IN THE HORIZONTAL PLANE, AND THUS ABSENCE OF 'CROSS-ANISOTROPY' ARE SUGGESTED. IT IS CONCLUDED THAT BOTH THE MORPHOLOGICAL AND THE MECHANICAL ANISOTROPY CAN BE DESCRIBED AS HAVING A MONOCLINIC SYMMETRY. ON THE BASIS OF ABUNDANT GEOLOGICAL FIELD EVIDENCE, THIS CHARACTERISTICC MAY BE MUCH MORE COMMON IN RECENT AS WELL AS IN OLDER BEACH SAND DEPOSITS THAN IS ANTICIPATED AT PRESENT. /CSIRO/

  • Corporate Authors:

    Commonwealth Scientific & Industrial Research Org

    314 Albert Street
    East Melbourne, Victoria,   Australia 
  • Authors:
    • Lafeber, D
    • Willoughby, D R
  • Publication Date: 1970

Media Info

  • Pagination: p. 80-6

Subject/Index Terms

Filing Info

  • Accession Number: 00230203
  • Record Type: Publication
  • Source Agency: Commonwealth Scientific & Industrial Research Org
  • Files: TRIS
  • Created Date: Aug 5 1973 12:00AM