NATURALLY CEMENTED SENSITIVE SOILS

MANY EXTREMELY SENSITIVE OR QUICK CLAY SOILS, PARTICULARLY T NOT ONLY THOSE FOUND IN CANADA, SHOW CHARACTERISTICS OF NATURAL CEMENTATION BONDING BETWEEN PARTICLES. THESE SOILS INCLUDE NOT ONLY THE BRACKISH-MARINE LEDA-TYPE CLAY DEPOSITS BUT ALSO FRESH WATER VARVED CLAYS, DEEP MARINE CLAYS AND OTHERS. ALTHOUGH THE CAUSES OF CEMENTATION MAY VARY, THE MECHANICAL BEHAVIOUR OF THESE SOILS IS SIMILAR. THE UNIQUE STRENGTH CHARACTERISTIC OF NATURALLY CEMENTED SOILS IS A YIELD CURVE, DEFINED BY BREAKDOWN OF CEMENTATION, WHICH IS INDEPENDENT OF THE CLASSICAL EFFECTIVE STRESS PATTERNS OF YIELDING OR FAILURE FOR SOILS. AT LOW STRESSES THE INFLUENCE OF CEMENTATION IS TO INCREASE STRENGTH AND RESISTANCE TO DEFORMATION. THE CEMENTATION YIELD CURVE CAN BIE GENERALIZED IN SECTIONS, A LIMIT AT A CONSTANT VALUE OF MEAN NORMAL STRESS INTERSECTING A LIMIT OF SHEAR STRESS OR STRESS DIFFERENCE. THIS PART OF THE YIELD CURVE IS OFTEN AT A CONSTANT VALUE OF SHEAR STRESS OVER A LARGE RANGE OF NORMAL STRESS. TENSILE STRENGTH IS SMALL. STRAINS UP TO YIELD, BOTH VOLUMETRIC AND DISTORTIONAL, ARE SMALL AND APPROXIMATELY LINEAR FUNCTIONS OF MEAN NORMAL STRESS AND SHEAR STRESS RESPECTIVELY. EXAMPLES FOR A VARIETY OF NATURALLY CEMENTED SOILD DEMONSTRATE THAT ANISOTROPY AND NONHOMOGENEOUS EFFECTS SUCH AS FISSURES AND VARVES ARE IMPORTANT (A).

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 139-52
  • Serial:
    • GEOTECHNIQUE
    • Volume: 22 N
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00230333
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: May 15 1974 12:00AM