Accession Number:

ADA222448

Title:

X-Ray Photography Method for Experimental Studies of the Frozen Fringe Characteristics of Freezing Soil

Descriptive Note:

Special rept.

Corporate Author:

COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

Personal Author(s):

Report Date:

1990-02-01

Pagination or Media Count:

88.0

Abstract:

The main objectives of this report are 1 To describe the development of an X-ray photographic method for observing the frost-heaving properties of soil, especially the characteristics of the frozen fringe 2 To describe observations of the temperature and strain field change in the frozen fringe using the procedure developed and 3 To publish the test results as a data base that can be used in evaluating frost heave models. The method used X-ray photography with thermocouples installed inside lead marking spheres to observe soil expansion, including expansion due to in-situ freezing and expansion due to segregation freezing. The method includes an image-processing technique for analyzing the coordinates of the lead spheres on the photos, a three-dimensional analysis of the lead spheres coordinates to compensate for the geometrical distortion caused by the use of a point X-ray source, and direct measurements of the temperature at each lead sphere using thermocouples in the spheres. Therefore, both the deformation and the temperature field in a freezing soil can be observed directly. Results on the following characteristics include Temperature profiles in two freezing soil specimens The expansion activity strain and strain rate distributions in two specimens The apparent temperature range of the frozen fringe The apparent thickness of the frozen fringe and The thermal conductivity of the frozen fringe while the warmest ice lens is segregating.

Subject Categories:

  • Soil Mechanics
  • Snow, Ice and Permafrost
  • Photography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE