THE SUCTION AND STRENGTH OF REMOULDED SOILS AS AFFECTED BY COMPOSITION

REMOULDED SOILS ARE WIDELY USED IN THE CONSTRUCTION OF EARTHWORKS. THIS REPORT DESCRIBES AN INVESTIGATION OF THE EFFECT OF THE COMPOSITION OF REMOULDED SOILS ON THEIR SUCTION AND STRENGTH PROPERTIES. MEASUREMENTS WERE MADE ON ARTIFICIAL SOIL MIXTURES CONSISTING OF PURE CLAY MINERALS MIXED WITH VARIOUS PROPORTIONS OF COARSE MATERIAL HAVING SELECTED FRICTIONAL CHARACTERISTICS. THE SHEAR STRENGTH WAS MEASURED WITH A LABORATORY VANE APPARATUS, AND THE SUCTION WAS MEASURED FREE OF EXTERNAL STRESS WITH A RAPID-METHOD APPARATUS SPECIALLY DEVELOPED DURING THE WORK AND HAVING AN EXTENDED RANGE. THE RESULTS WERE CONSIDERED BOTH FROM THE POINT OF VIEW OF THE SUCTION, WHICH DETERMINES THE EQUILIBRIUM MOISTURE CONTENT OF A SOIL UNDER STEADY CONDITIONS, AND FROM THE POINT OF VIEW OF THE MOISTURE CONTENT, WHICH IS THE PARAMETER MOST WIDELY MEASURED IN ENGINEERING PRACTICE. IT WAS FOUND THAT THE STRENGTH IS APPROXIMATELY PROPORTIONAL TO SUCTION FOR A GIVEN SAMPLE. FOR A RANGE OF SAMPLES WHOSE COARSER GRAINS HAVE VARYING DEGREES OF ANGULARITY, IT WAS FOUND THAT THE STRENGTH FOR A PARTICULAR SUCTION INCREASES WITH INCREASING ANGULARITY OF THE COARSER GRAINS, BUT IS LITTLE AFFECTED BY THE LIQUID LIMIT OF THE CLAY FRACTION. AS THE PROPORTION OF CLAY DECREASES, THE STRENGTH AT A GIVEN SUCTION INCREASES IF THE COARSE GRAINS ARE ANGULAR, BUT IS UNAFFECTED IF THEY ARE ROUNDED. THE LOGARITHM OF BOTH THE SUCTION AND THE STRENGTH OF A SOIL DECREASES APPROXIMATELY LINEARLY AS THE MOISTURE CONTENT INCREASES. FOR A GIVEN MOISTURE CONTENT, BOTH SUCTION AND STRENGTH INCREASE AS THE PROPORTION AND THE LIQUID LIMIT OF THE CLAY INCREASES, BUT IN PRACTICE A SOIL WITH A HIGHER LIQUID LIMIT WILL OCCUR AT A HIGHER NATURAL MOISTURE CONTENT. THE STRENGTH INCREASES AS THE GRAIN ANGULARITY OF THE COARSE FRACTION INCREASES, BUT THE SUCTION IS UNAFFECTED. THE RESULTS LEAD TO THE PRACTICAL CONCLUSION THAT LARGE ARTIFICIAL ADDITIONS OF SANDY MATERIAL TO A CLAY SOIL WOULD PRODUCE ONLY RELATIVELY SMALL INCREASES IN STRENGTH AT A GIVEN SUCTION, AND SIMILARLY THAT CONSIDERABLE NATURAL VARIATIONS IN CLAY CONTENT AND CLAY MINERAL TYPE ON A SITE WOULD PRODUCE A MUCH GREATER EFFECT ON THE LIQUID AND PLASTIC LIMITS THAN ON THE SHEAR STRENGTH AT A GIVEN SUCTION. /RRL(A)/

  • Supplemental Notes:
    • Rrl Rept Lr 306, 38 PP, 19 FIG, 2 TAB, 1 PHOT, 13 REF
  • Corporate Authors:

    Road Research Laboratory /UK

    ,    
  • Authors:
    • Dumbleton, M J
    • WEST, G
  • Publication Date: 1970

Subject/Index Terms

Filing Info

  • Accession Number: 00234902
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS, ATRI
  • Created Date: Oct 18 1971 12:00AM