Accession Number:

ADA196742

Title:

Summary of Methods for Measuring Electrical Properties of Geological Strata to Estimate Electromagnetic Shielding Effectiveness

Descriptive Note:

Final technical rept.

Corporate Author:

CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL

Report Date:

1988-04-01

Pagination or Media Count:

99.0

Abstract:

This investigation was performed under Project 4A162731AT41, Military Facilities Engineering Technology, Work Unit CO-054, Electromagnetic Pulse EMP Validation of Design Recommendations for C3I Facilities. Principal electrical properties of interest are the dielectric constant and conductivity or resistivity. Representative measured results reported in the literature for various rock and soil types are included. The measurement techniques considered are 1 laboratory methods 2 in situ measurements at the surface of the Earth and 3 in situ drill-hole measurement methods. Because many factors influence the electrical constants of the real earth, it is highly desirable, when practical, to perform measurements in situ rather than in the laboratory. Methods based on single drill holes provide localized values for the electrical constants in the vicinity of the hole. Propagation between two holes can be used to deduce bulk characteristics of earth medium electrical constants between the two holes. Since characterizing a broad area of the Earths surface would require data from a large number of holes, this method can be quite expensive. When it becomes impractical to drill holes, in situ surface measurement methods can be substituted. Keywords Dielectric properties, Electrical conductivity of soils, Electrical measurement of rock.

Subject Categories:

  • Geology, Geochemistry and Mineralogy
  • Electromagnetic Shielding
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE