A Temperature Based Novel Monitoring System for Scour and Deposition at Bridge Piers

Stream flows around a bridge pier can be fast and highly turbulent causing large shear stresses that may mobilize streambed sediment resulting in scour around bridge foundations. Scour is the leading cause of bridge failure in the USA because it compromises bridge structural stability. However, streambed surface elevation may decrease (sediment scour) or increase (deposition of sediment) depending on local upstream sediment transport and water flow conditions. Consequently, yearly or biyearly measurements of streambed elevations may not provide an accurate evaluation of the scour risk at bridges. Current techniques are too expensive, difficult to install or provide only maximum scour. Thus, this project tests a low-cost and simple methodology to monitor streambed elevation changes continuously. The method uses the naturally occurring oscillations of stream water temperature as a tracer. As the water temperature signal propagates through the sediment, it undergoes advection dispersion and diffusion, which change the phase and amplitude of the original signal (stream water temperature). The proposed method detects changes in local streambed elevation from paired analysis of the phase and amplitude of in-stream and in-sediment water temperature signals. The test at five Idaho bridges in five different watersheds proves that the method is robust. The method detects streambed elevation changes and maximum scour, which are verified with time series of ground-surveyed streambed elevations and scour chains, respectively.

• Record URL:
  http://apps.itd.idaho.gov/apps/research/Completed/RP243.pdf
• 
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/34945
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/63581
• Corporate Authors:

  University of Idaho, Boise

  Center for Ecohydraulics
  Boise, ID  United States 

  United States Forest Service

  ,    

  Idaho Transportation Department

  Division of Engineering Services, Contracting Services, Research Program
  P.O. Box 7129
  Boise, ID  United States  83707-7129

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Carpenter, Aston M
  • Tonina, Daniele
  • Luce, Charles H
• Publication Date: 2017-5

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; Maps; Photos; References; Tables;
• Pagination: 40p

Subject/Index Terms

• TRT Terms: Bridge piers; Deposition; Methodology; Monitoring; Scour; Streambeds; Temperature; Time series analysis
• Geographic Terms: Idaho
• Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology; Maintenance and Preservation;

Filing Info

• Accession Number: 01665921
• Record Type: Publication
• Report/Paper Numbers: FHWA-ID-17-243, RP 243
• Contract Numbers: UI-15-03
• Files: NTL, TRIS, ATRI, USDOT, STATEDOT
• Created Date: Apr 11 2018 5:21PM