Inclinometer - Time Domain Reflectometry Comparative Study

Details

• Creators:
  Sargand, Shad M. ; Sargent, Lisa ; Farrington, Stephen P.
• Corporate Creators:
  Ohio University. Ohio Research Institute for Transportation and the Environment (ORITE)
• Corporate Contributors:
  Ohio. Dept. of Transportation. Office of Research and Development ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Shear strength
  • Soils by strength
  • Time domain reflectometers
  • Testing Shear strength of soils--Testing
  • Inclinometer--Testing
  • Time-domain reflectometry--Testing
• Publication/ Report Number:
  FHWA/OH-2004/010
• Resource Type:
  Tech Report
• Geographical Coverage:
  Ohio
• Edition:
  Final technical report.
• Corporate Publisher:
  Ohio Research Institute for Transportation and the Environment
• Abstract:
  Four pairs of inclinometers and time domain reflectometry (TDR) cables were set up to make a side-by-side ; comparison of the performance of these systems in detecting slippage of soils in the shoulders of State Route 124 ; and State Route 338 in Meigs County, Ohio, within 50 feet (15 m) of the Ohio River. The soil consisted of sandy ; silt, silt, and clay on top of sedimentary rock. Borings were located 3-6 ft (1-2 m) from the edge of the pavement on ; the shoulder of the road at two locations on each road, with a TDR and an inclinometer located 3-5 ft (1-1.7 m) ; apart. Borings extended 10 ft (3.3 m) into the bedrock. Sixteen monthly readings were taken. ; At all four locations, the inclinometers detected shearing at depths ranging from 16 ft (4.9 m) to 40 ft (12.2 m). ; All of the detected shears were also identified by the TDR cables to within 1 ft (0.3 m). Water leakage occurred at ; shear locations on two TDR cables, preventing further monitoring below that depth on each; one inclinometer was ; also deformed beyond use at the same depth as the corresponding TDR cable water leakage. ; The cost for materials and casing for a single inclinometer installation is $484, versus $316 for a TDR, a ; reduction of 34.71%. The data acquisition and analysis equipment costs are $11,245 and $5,110 respectively, for a ; reduction of 54.56%. The total savings for a TDR system is 53.74%. For an additional $3105, remote monitoring of ; TDR installations can be added, eliminating the need for site visits until the cable becomes damaged; the TDR ; system savings even with the remote monitoring are still 27.27% over the inclinometer. Labor time costs for initial ; installation are comparable at 8-12 hours, while the reading time is reduced from 10-30 minutes for an inclinometer ; to 1 minute for a TDR system. TDR cables also have the advantage that they can be extended to a safer or more ; accessible point for reading.
  More +
• Format:
  PDF
• Funding:
  14798(0)
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18218/dot_18218_DS1.pdf
• File Type:
  [PDF - 4.64 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:ceb3176ef2eae967ccfdfb7597eee7ecc2bcaaccc74143f0c20e9aeae077d40dadd249e7cdcb1646d9f3f56ce9a76cf751efd2dc8f58d182fe6ff357f54a1bad