Assessment of karst activity at highway construction sites using the electrical resistivity method (Greene and Jefferson Counties, Missouri).

Details

• Creators:
  Anderson, Neil L. ; Apel, Derek B. ; Ismail, Ahmed
• Corporate Creators:
  Missouri. Department of Transportation
• Corporate Contributors:
  United States. Department of Transportation. University Transportation Centers (UTC) Program ; United States. Department of Transportation. Research and Special Programs Administration
• Subject/TRT Terms:
  • Karst
  • Resistivity method
  • Pavements
  • Pavements--Missouri--Testing
  • Karst--Missouri
• Publication/ Report Number:
  OR 07-003
• Resource Type:
  Tech Report
• Geographical Coverage:
  Missouri
• Edition:
  Final report.
• Corporate Publisher:
  University of Missouri--Rolla. Center for Infrastructure Engineering Studies
• Abstract:
  Two-dimensional (2-D) electrical resistivity data were acquired across and in proximity to active sinkholes at two Missouri ; Department of Transportation (MoDOT) highway-construction sites. Construction site #1 is located in Greene County, Missouri; ; site #2 is located in Jefferson County, Missouri. ; Two relatively dense grids (“1A” and “1B”) of electrical resistivity data were acquired at Greene County site #1 as part of a ; geotechnical investigation of a proposed interchange. Several active sinkholes with exposed throat diameters on the order of 1.5 ft ; had been discovered during a routine visual inspection of the site, and the District Geologist decided that a geophysical ; investigation was warranted prior to routine boring. The primary objective of the electrical resistivity study was to determine if ; substantive air-filled karstic cavities were present in the subsurface. Secondary objectives were to estimate depth to bedrock and ; identify anomalous subsurface conditions that might compromise the integrity of the proposed intersection or complicate ; construction. The electrical resistivity data proved to be of significant utility. Substantive air-filled voids were not imaged on the ; resistivity profiles. A depth to bedrock structure contour map was generated for the site, and prominent clay-filled and apparently ; inactive karstic cavities were identified beneath segments of proposed new roadway. ; A relatively dense grid of electrical resistivity data was also acquired at Jefferson County site #2. These electrical resistivity data ; were acquired because a previously unmapped, oval-shaped, clay-filled, sinkhole (approximately 50 ft x 35 ft x 15 ft; length x ; width x height) near the centerline of the northbound lanes effectively “emptied” overnight after overlying soil had been stripped ; by earth moving equipment. The supervising geologist authorized the acquisition of the geophysical data in order to image the ; subsurface immediately beneath and adjacent to the sinkhole. The primary concern was that the sinkhole was underlain by a large ; air-filled cavity. The interpretation of the resistivity data indicated the reactivated sinkhole was not underlain by a substantive ; cavity. Rather, the soil in the sinkhole appears to have “flowed” into the subsurface through solution-widened system of joints ; that do not underlie the sinkhole and probably do not pose a significant risk in terms of catastrophic collapse under load.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/17417/dot_17417_DS1.pdf
• File Type:
  [PDF - 1.09 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:f62cce9ba6499d5ca83e9e1dafe49ac4a341d8e2b1231453414b4a073f7a325a