Identification of expansive soils using remote sensing and in-situ field measurements : phase I.

Details

• Creators:
  Coffman, Richard A. ; Garner, Cyrus D.
• Corporate Creators:
  Mack-Blackwell National Rural Transportation Study Center (U.S.)
• Corporate Contributors:
  University Transportation Centers Program (U.S.)
• Subject/TRT Terms:
  Expansive Clays Laser Radar Moisture Content Remote Sensing Soil Water Swelling Soils
• Publication/ Report Number:
  MBTC DOT 3031
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Dept. of Transportation. Research and Special Programs Administration
• NTL Classification:
  NTL-HIGHWAY/ROAD TRANSPORTATION-Soils and Geology
• Abstract:
  Researchers at the University of Arkansas have conducted research on the suitability of using remote sensing techniques (radar and LIDAR) to monitor the shrink-swell behavior of an expansive clay material in a field test site as part of the Mack Blackwell Rural Transportation Center Project 3031. The field test site consisted of two 5,000 square foot compacted clay pads installed at the University of Arkansas’ Cato Springs Research Center (CSRC). In Phase I-A of the project four LIDAR scans and 335 radar scans were captured over an eight month period. The pads were constructed of eight inches of compacted clay material sourced from a local supplier overlying a two inch sand blanket. One pad was amended by the addition of three percent sodium bentonite (by dry weight) to increase the expansive behavior of the material. Radar scans were conducted on a weekly basis or after significant precipitation events. Additionally in Phase I-B, an additional three percent bentonite was added to the expansive pad and both pads were reconstructed. Results generated by this research project indicate that the LIDAR was able to detect the presence of ground movement due to expansive material. However, processing limitations severely curtailed the accuracy of this method. There were several issues encountered with the installation of the in-situ monitoring equipment in the compacted clay. Further research is required to determine the optimum method of installing TDR probes in compacted clay. TDR probes and tensiometers were used to develop the soil water characteristic curve. However, the pads did not experience a large enough change in volumetric water content to develop a large portion of the curve.
• Format:
  PDF
• Collection(s):
  University Transportation Centers US Transportation Collection
• Main Document Checksum:
  urn:sha256:c2cd8564036f5ea0f061a227f01baf1d90974320f115f96f07b56bf347fb2cbf
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/26004/dot_26004_DS1.pdf
• File Type:
  [PDF - 5.21 MB ]