Electrical resistivity measurement of mechanically stabilized Earth wall backfill : final report.

Details

• Creators:
  Tucker-Kulesza, Stacey ; Snapp, Michael ; Koehn, Weston
• Corporate Creators:
  Kansas State University. Transportation Center ; Kansas State University. Department of Civil Engineering
• Corporate Contributors:
  Kansas. Dept. of Transportation. Bureau of Research
• Subject/TRT Terms:
  • Algorithms
  • Backfill soils
  • Coarse aggregates
  • Electrical resistivity
  • Retaining walls
  • Mechanically stabilized Earth wall backfill
  • electrical resistivity imaging
  • coarse aggregate
• Publication/ Report Number:
  K-TRAN: KSU-15-6
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Kansas
• Edition:
  Final report, July 2014-March 2016
• Corporate Publisher:
  Kansas. Dept. of Transportation
• Abstract:
  In Kansas, mechanically stabilized earth (MSE) retaining walls are typically backfilled with coarse aggregate. ; Current backfill material testing procedures used by the Kansas Department of Transportation (KDOT) utilize on-site ; observations for construction quality assurance and the American Association of State Highway and Transportation ; Officials (AASHTO) Standard T 288-12 (2012), “Standard Method of Test for Determining Minimum Laboratory Soil ; Resistivity.” T 288 is designed to test a soil sample’s electrical resistivity, which correlates to its corrosive potential. ; The test, based on material passing through a No. 10 sieve, is considered inappropriate for coarse aggregates and ; potentially leads to over-conservative designs. Additionally, T 288 is run on a sample from the aggregate source, but ; test results may not capture variability of the aggregate used in construction. Electrical resistivity imaging (ERI) ; provides a two-dimensional (2D) profile of the bulk resistivity of backfill material, thereby reducing uncertainty ; regarding backfill uniformity as compared to traditional sampling. The objective of this study was to characterize bulk ; resistivity of in-place MSE wall backfill aggregate using ERI. ERI was used on six walls: five MSE walls and one ; gravity retaining wall that contained no reinforcement. The ERI field method produced a 2D profile that depicted ; electrical resistivity uniformity for bulk analysis. A post-processing algorithm was developed to calculate the bulk ; electrical resistivity of the backfill and reduce the qualitative interpretation of the ERI results. These results indicate ; that the laboratory analysis of T 288 underestimates the bulk electrical resistivity of in situ backfill material. ; Recommendations of the study were that ERI surveys and calculated mean electrical resistivity be utilized as ; construction quality assurance in order to reduce uncertainty of current selection practices.
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• Format:
  PDF
• Funding:
  C2032
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/30912/dot_30912_DS1.pdf
• File Type:
  [PDF - 2.35 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:c7709c22f101bc748640819985a9b09452678b3265e1d7a484e2b5599cc66e24