Technical Reports

Ground Penetrating Radar for Railroad Track Substructure Evaluation

  • 01
  • Oct
  • 2005
AUTHOR: J.P. Hyslip (1). G.R. Olhoeft(2), S.S. Smith(3), E.T. Selig(4)
OFFICE: RPD
REPORT NUMBER: DOT/FRA/ORD-05/04
KEYWORDS: Railroad, substructure, ground penetrating radar, track maintenance, ballast, subballast, subgrade, non-destructive testing
ABSTRACT: This report presents the results of the first three phases of a multiphase project to adapt Ground Penetrating Radar (GPR) to railroads for use in developing useful indices of substructure condition and performance. Included are brief discussions of some basic GPR principles, as well as data processing and modeling techniques that are applicable to railroad surveys. The railway GPR equipment is mounted on a hi-rail vehicle and includes multiple sets of 1-GHz air-launched horn antennas suspended above the track that permit fast survey travel speeds and high resolution measurements to a depth of 1 to 2 m. The multiple sets of antennas provide transverse and longitudinal measurements of the track structure. This report presents example results from more than 200 miles of surveys to demonstrate the capabilities and applicability of GPR to assess railway track substructure (ballast, subballast, and subgrade) conditions and to produce quantitative indices of railway track substructure condition for use in track substructure maintenance management efforts.

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