Compare NCDOT Bridge Scour Calculations to USGS SIR 2016-5121 South Carolina (SC) Scour Envelope Curves Results

The North Carolina Department of Transportation (NCDOT) routinely performs assessment of scour potential at bridge foundations. The availability of representative approaches for estimating first order scour magnitude is needed as such information is used for the design of new bridges, designating bridges as “scour- critical,” and for deciding on the need for implementing scour countermeasures. Such investigation is needed to assess the robustness of the first order scour estimates and to provide reliable quality control measure to ensure the reasonableness of bridge scour magnitudes estimated by other means. The research proposed herein aims at assessing the accuracy of the scour predictions and assessment methodology of the Scour Envelope curves to the geologic regions of North Carolina. The proposed approach will focus on collating existing datasets and measurements of bridge scour across North Carolina. We will estimate bridge scour using three different methods: the SC Scour Envelope Curves, the FHWA HEC-18 method, and numerically modeling the bridge sites with Delft3D. These three methods will be applied to a variety of sites throughout NC. In addition to using existing datasets, and using remote sensing to discern the study sites geometrical attributes, we will measure flow conditions (using our Acoustic Doppler Current Profiler (ADCP) upstream, downstream, and at the bridge. We will also deploy an Acoustic Doppler Velocimeter (ADV) to measure current and turbulence at specific depths in and around the bridge pier. This field work will only be performed at select sites for more detailed calibration of our numerical modeling. All of our results will be uploaded to rasters maps in ArcGIS for easy comparison of estimated scour for the 50, 100, and 500-year flood events between the different methods. We will then compare between the methodologies to suggest the best procedure for the NCDOT to use weighing accuracy, time, and ease of estimation. The study will culminate in providing NCDOT with recommendation of an approach for estimation of the magnitude of sediment scour at bridge sites for the range of bed geologic materials in North Carolina.

    Project

    • Status: Active
    • Funding: $335,480
    • Sponsor Organizations:

      North Carolina Department of Transportation

      Research and Development
      1549 Mail Service Center
      Raleigh, NC  United States  27699-1549
    • Managing Organizations:

      North Carolina Department of Transportation

      Research and Development
      1549 Mail Service Center
      Raleigh, NC  United States  27699-1549
    • Project Managers:

      Kirby, John

    • Performing Organizations:

      North Carolina State University

      Department of Civil, Construction and Environmental Engineering
      2501 Stinson Drive
      Raleigh, NC  United States  27695
    • Principal Investigators:

      Montoya, Brina

    • Start Date: 20190801
    • Expected Completion Date: 20210731
    • Actual Completion Date: 0

    Subject/Index Terms

    • TRT Terms: Hydraulics
    • Subject Areas: Environment;

    Filing Info

    • Accession Number: 01716168
    • Record Type: Research project
    • Source Agency: North Carolina Department of Transportation
    • Files: RiP, STATEDOT
    • Created Date: Sep 16 2019 2:34PM