LABORATORY INVESTIGATION OF UNDISTURBED SAMPLING OF COHESIONLESS MATERIAL BELOW THE WATER TABLE

This report describes the results obtained in a laboratory program designed to evaluate the quality of undisturbed samples. A Hvorslev fixed-piston sampler and drilling mud were used to obtain undisturbed sand samples in homogeneously prepared specimens 4 ft in diameter and 6 ft high. Construction of a homogeneous specimen 4 ft in diameter and 6 ft high is no small feat. Various techniques were used during the course of this study for specimen preparation. As-built density determinations indicate that the variation of placed density is approximately -1.5 to +2.9 pcf. Undisturbed samples 3 in. in diameter were obtained at different overburden pressures. These samples were sealed with end packers and stored overnight in a vertical position. The following day each tube was placed in a horizontal position in a wooden carrying rack, and the top of each tube was marked for orientation purposes. Each tube was then tapped 50 times with a rubber hammer to consolidate the material prior to handling. The tube was then cut into 6-in. segments for laboratory density determinations. A statistical comparison of the sampled density to the corrected "as built" density was conducted. This comparison indicates that the sampling accuracy is within plus minus 3.4 pcf 95 percent of the time.

  • Corporate Authors:

    U.S. Army Waterways Experiment Station

    Soils and Pavement Laboratory
    Vicksburg, MS  USA  39180
  • Authors:
    • COOPER, S S
  • Publication Date: 1976-10

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 68 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00142966
  • Record Type: Publication
  • Report/Paper Numbers: Res. Rpt. 5-76-1 Final Rpt.
  • Files: TRIS
  • Created Date: Dec 22 1976 12:00AM