ELECTROMAGNETIC INDUCTION MEASUREMENTS IN PERMAFROST TERRAIN FOR DETECTING GROUND ICE AND ICE-RICH SOILS

A major problem associated with geotechnical engineering in Alaska is the characterization of foundation soils with sufficient sampling locations to describe lateral changes in properties. Logged holes are the most reliable form of foundation exploration, but are prohibitively expensive in cases where delineation of small but structurally significant features might, for example, require 10 foot drilling centers. Fortunately, borehole data can often be both interpolated and extrapolated through careful interpretations of ground resistivity data. This report describes the magnetic induction method for resistivity measurement as employed in the EM-31 instrument (Geonics Ltd., Canada). The EM-31 is relatively inexpensive compared with other foundation exploration tools, is highly portable, and rapidly measures soil resistivity values without ground contact. Details of EM-31 applications are fully discussed through presentation of 22 case histories of sites throughout Alaska. Results of this study show the EM-31 to be a valuable aid in distinguishing between frozen and unfrozen soils, and in estimating ice contents. The device also proved useful in mapping geothermal sites where resistivity measurements were effected by temperature and silinity variations. It was recommended that an EM-31 or equivalent device be used routinely on all transportation related construction sites in Alaska. (Author)

• Record URL:
  http://www.dot.state.ak.us/stwddes/research/assets/pdf/fhwa_ak_rd_85_12.pdf
• 
• Corporate Authors:

  University of Alaska, College

  Geophysical Institute
  College, AK  United States  99701

  Alaska Department of Transportation and Public Facilities

  Pouch Z
  Juneau, AK  United States  99811

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Kawasaki, Kunihiro
  • Osterkamp, T E
• Publication Date: 1984-12

Media Info

• Features: Figures; References; Tables;
• Pagination: 197 p.

Subject/Index Terms

• TRT Terms: Detectors; Electrical resistivity; Electromagnetic induction; Geotechnical engineering; Ice; Measuring instruments; Permafrost; Portable equipment
• Uncontrolled Terms: Ground
• Old TRIS Terms: Detecting devices; Resistivity
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00453719
• Record Type: Publication
• Report/Paper Numbers: FHWA-AK-RD-85-12
• Contract Numbers: F36312
• Files: TRIS, USDOT, STATEDOT
• Created Date: May 31 1987 12:00AM