FORCES ON AN OPEN-DRIVE SAMPLER IN STIFF CLAY

DURING A SERIES OF TESTS ON SAMPLING OPERATIONS CARRIED IN FIRM TO STIFF CLAY USING A 3-IN. THIN- WALLED, OPEN DRIVER SAMPLER, THE FORCES APPLIED TO THE SAMPLER, AND THE DISPLACEMENTS OF THE SAMPLER AND THE SOIL SAMPLE WERE MEASURED AND RECORDED ELECTRICALLY. IMMEDIATE UNDRAINED TRIAXIAL COMPRESSION TESTS WERE MADE ON 3-IN. DIAMETER SPECIMENS CUT FROM THE TUBE SAMPLES. THE TWO METHODS USED FOR ESTIMATING WHAT PROPORTION OF THE TOTAL APPLIED FORCE WAS TRANSMITTED FROM THE INSIDE OF THE SAMPLE TUBE TO THE SAMPLE WERE BASED ON MEASUREMENTS MADE ON THE WITHDRAWAL FORCE AND THE INTRUSION FORCE. FOR THE PEAK VALUES OF THE FORCES, MEAN RATIOS (INSIDE FORCE/TOTAL FORCE) OF 0.48 OR 0.28, RESPECTIVELY, WERE OBTAINED. BOTH DURING ADVANCE AND WITHDRAWAL OF THE SAMPLER, THE AVERAGE SURFACE SHEAR STRESS ON THE AREA IN CONTACT WITH THE SOIL REACHED 0.64 TIMES THE SHEAR STRENGTH OF THE SOIL. THE PEAK AXIAL STRESS ON THE SOIL CORE REACHED A MEAN VALUE OF 13.4 TIMES THE SHEAR STRENGTH OF THE SOIL. THIS WAS HIGHER THAN THAT PREDICTED FROM A SIMPLE, THEORETICAL MODEL. ANALYSIS OF THE TEST RESULTS SHOWS THAT FOR PAIRS OF SPECIMENS CUT FROM THE SAME TUBE SAMPLE THE LOWER SPECIMENS CONSISTENTLY INDICATED HIGHER STRENGTHS THAN THE UPPER SPECIMENS. THE DIFFERENCE EXCEEDS THAT WHICH COULD BE ACCOUNTED FOR BY OTHER CAUSES, AND IS THEREFORE ATTRIBUTED TO THE SAMPLING PROCESS. /CSIRO/

Media Info

  • Pagination: p. 21-9
  • Serial:
    • Volume: 2

Subject/Index Terms

Filing Info

  • Accession Number: 00230207
  • Record Type: Publication
  • Source Agency: Commonwealth Scientific & Industrial Research Org
  • Files: TRIS
  • Created Date: Aug 5 1973 12:00AM