STRUCTURAL BEHAVIOUR OF RESIDUAL SOILS OF THE CONTINUALLY WET HIGHLANDS OF PAPUA, NEW GUINEA

THE PAPER ILLUSTRATES HOW HIGH POROSITY, A STRONGLY CEMENTED STRUCTURE AND HIGHLY HYDRATED KANDITE CLAY MINERALS CONTROL THE GEOTECHNICAL PROPERTIES OF RESIDUAL SANDY TO SILTY CLAY SOILS OF THE PAPUA NEW GUINEA HIGHLANDS. THESE SOILS ARE CHARACTERIZED BY HIGH FIELD MOISTURE CONTENTS, RELATIVELY HIGH SHEAR STRENGTHS AND LOW SENSIVITY, AND ARE HIGHLY COMPRESSIBLE WHEN THE APPLIED PRESSURE IN AN OEDOMETER TEST EXCEEDS A CERTAIN CRITICAL PRESSURE. MEASURED VALUES OF CRITICAL PRESSURE AND COMPRESSION INDEX ARE COMPARED WITH THOSE REPORTED FOR A WIDE VARIETY OF SOILS, AND A LINEAR RELATION BETWEEN VOLUMETRIC STRAIN AND POROSITY IS ESTABLISHED FOR POROUS SOILS. THE NATURAL INHOMOGENEITY OF RESIDUAL SOILS IS EMPHASIZED. EXAMINATION OF RELATIONS BETWEEN GEOTECHNICAL PROPERTIES AND POROSITY AND MOISTURE CONTENT SHOWS THAT POROSITY OR DRY DENSITY IS A MORE REASONABLE BASIS FOR DESCRIPTION AND GROUPING OF THESE SOILS FOR ENGINEERING PURPOSES. THE BEHAVIOUR OF THE SOILS IS INTERPRETED IN TERMS OF AN IDEALIZED MODEL OF THE SOIL STRUCTURE. THE SOIL IS CONSIDERED TO CONSIST OF A COARSE OPEN SKELETON OF CEMENTED ROCK MINERAL AND AGGREGATED CLAY PARTICLES SURROUNDED BY A VISCOUS GEL. AT LOW APPLIED STRESSES, WHEN THE CEMENTED BONDS IN THE SOIL SKELETON ARE INTACT, IT IS THE SOIL SKELETON THAT DETERMINES STRUCTURAL BEHAVIOUR. AT HIGH APPLIED STRESSES THE POROUS SOIL SKELETON STILL HAS A STRONG INFLUENCE ON STRUCTURAL BEHAVIOR. /AUTHOR/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 203-18
  • Serial:
    • GEOTECHNIQUE
    • Volume: 23
    • Issue Number: 2
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00230483
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: Apr 27 1974 12:00AM