A DEVICE FOR EVALUATION OF THAW WEAKENING OF FROST-SUSCEPTIBLE SOIL

As a soil freezes unidirectionally, water is drawn up to the freezing front and, under appropriate conditions, ice lenses form. As thawing progresses downward, water, which formerly constituted an ice lens, remains perched above the still frozen subsoil. These localized zones exhibit shear resistances below their prefreeze values. A direct simple shear (DSS) device used to investigate this phenomenon on a thawed sample is described. The sample is the upper layer of a large cylindrical specimen that has been thermally conditioned under a carefully controlled laboratory environment. The controlled environment is produced by a frost cabinet with two independent refrigeration units to cool both the air above the specimen and a water supply to the base of the specimen. Either an open or a closed water supply system can be used. After the desired thermal history has been created and the specimen is completely frozen, sequential thawing and simple shear testing begins from the top downward. A carefully controlled heating element thaws the specimen from the top, leaving a thin shear sample. The top surface of the sample is approximately parallel to the bottom surface (the freeze-thaw interface). Undrained, shear testing is then performed. The frozen sublayers inhibit downward drainage, and a reinforced rubber membrane inhibits lateral drainage, thereby effectively duplicating field conditions. The sample is then removed, and the moisture content is determined. Shear testing continues at various elevations down through the specimen. The shear strength and moisture content versus depth profile is obtained for the initially created thermal history. Results from such tests using the DSS device performed on a frost-susceptible silty sand are presented. (Author)

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1983/918/918-002.pdf
• Summary URL:
  • https://scholar.google.com/scholar_lookup?title=A+DEVICE+FOR+EVALUATION+OF+THAW+WEAKENING+OF+FROST-SUSCEPTIBLE+SOIL&author=G.+Gifford&author=R.+D%27Andrea&author=J.+Sage&publication_year=1983
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• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Frost Action. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Gifford, G P
  • D'Andrea, R A
  • Sage, J D
• Conference:
  • 62nd Annual Meeting of the Transportation Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1983-1-17 to 1983-1-21
• Publication Date: 1983

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 10-15
• Monograph Title: FROST ACTION ON TRANSPORTATION FACILITIES
• Serial:
  • Transportation Research Record
  • Issue Number: 918
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Depth; Frost susceptible soil; Ice formations; Measuring instruments; Moisture content; Shear strength; Shear tests; Thaw
• Uncontrolled Terms: Ice lenses
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00381781
• Record Type: Publication
• ISBN: 030903561
• Files: TRIS, TRB
• Created Date: Mar 30 1984 12:00AM