ELECTROMAGNETIC CROSS-BOREHOLE SURVEY OF A SITE PROPOSED FOR AN URBAN TRANSIT STATION

LLL has developed and tested an electromagnetic method for probing between boreholes and has applied the method to characterize the site for a future urban rapid-transit station--the Forest Glen/Georgia Avenue station Washington, DC. Using this technique, the subsurface region's transmission properties were determined by sending a continuous-wave (cw) electromagnetic signal between a transmitter and a receiver in different boreholes. From the network of sampled signals, which vary according to the electrical properties of the media through which they pass, the region's properties can be determined. For the Forest Glen/Georgia Avenue site, there has been an excellent correlation of the predicted subsurface geologic structure and fracture density with the borehole core information. This suggests that cross-borehole probing has significant merit for inferring the detailed structure between boreholes. This is a desired capability that no other technique meets with as high a resolution as the described procedure.

  • Corporate Authors:

    University of California, Livermore

    Lawrence Livermore National Laboratory
    Livermore, CA  USA  94550

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  USA  20585
  • Authors:
    • Lytle, R J
    • Dines, K A
    • Laine, E F
    • Lager, D L
  • Publication Date: 1978-6-5

Media Info

  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00192188
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: W-7405-ENG-48
  • Files: TRIS
  • Created Date: Sep 15 1981 12:00AM