STATE OF THE ART OF UNDISTURBED SAMPLING OF COHESIONLESS SOILS

An important phase of any major site investigation is the obtaining of high-quality undisturbed samples of the subsurface materials. This report describes the current state of the art in obtaining undisturbed samples of cohesionless material - specifically, sands, silts, gravels, and mixtures - primarily as it is reflected in the experience of the Waterways Experiment Station (WES) and of others on the North American continent. The report discusses general considerations in planning an undisturbed sampling programme; methods of access to the soil materials for sampling, testing, or observation; and methods of sampling cohesionless soil. Methods of access and methods of sampling are described in tables which also note the areas of applicability of the various methods, important limitations and pitfalls, and important references. It offers further discussions on special considerations in methods of sampling, such as characteristics of sampling devices, drilling fluids, and sample intervals; the care of soil samples; and evaluation of sample disturbance. It is concluded that: (a) high quality, undisturbed samples of many sands can be obtained with a fixed-piston sampler and drilling mud, with proper care and attention to details of sampling, handling, and transportation. This sampling process yields very good samples of medium dense sands, but tends to densify loose sands and loosen dense sands; (b) the use of radiographs is recommended as a nondestructive method of evaluating sample disturbance; (C) in gravels, the only proven means of recovering undisturbed samples is by hand-carving block samples; and (D) recent studies indicate that freezing in situ, followed by coring, offers a promise for obtaining undisturbed samples of much higher quality than is possible with current practice. (Author/TRRL)

  • Availability:
  • Corporate Authors:

    Southeast Asian Society of Soil Engineering

    P.O. Box 2754
    Bangkok,   Thailand 
  • Authors:
    • Marcuson III, W F
    • Franklin, A G
  • Publication Date: 1980-6

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 31-53
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00330803
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Aug 15 1981 12:00AM