Application of Bridge Pier Scour Equations for Large Woody Vegetation

Existing bridge pier scour prediction equations exclude the influence of tree roots and the cross slope of levee embankments. Developed for specific conditions, these equations do not include modeling of scour at trees near or on levee embankments. Therefore, existing bridge pier scour models must be carefully evaluated and possibly modified before being applied to tree scour. The research conducted by the U.S. Army Engineer Research and Development Center (ERDC) included review and evaluation of the Sheppard-Melville and the Federal Highway Administration Hydraulic Engineering Circular No. 18 (FHWA HEC-18) bridge pier scour equations and validation flume experiments. The research objective was to provide guidance for predicting maximum scour depths near trees on or near levee embankments. The Sheppard-Melville and the HEC-18 methods of bridge pier scour prediction were evaluated. Results from the flume experiments indicate that both methods consistently over-predict scour depth by as much as 25 to 75 percent. Although other bridge scour equations can be used, both the Sheppard-Melville and the HEC-18 equations are sufficient in assessing tree scour potential to conservatively estimate maximum scour that may occur.

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  • Corporate Authors:

    U.S. Army Engineer Research and Development Center

    Geotechnical and Structures Laboratory, 3909 Halls Ferry Road
    Vicksburg, MS  United States  39180-6199

    U.S. Army Engineer Research and Development Center

    Coastal and Hydraulics Laboratory
    3909 Halls Ferry Road
    Vicksburg, MS  United States  39180-6199

    Institute for Water Resources

    Risk Management Center
    Lakewood, CO  United States 

    U.S. Army Corps of Engineers

    441 G Street, NW
    Washington, DC  United States  20314-1000
  • Authors:
    • Yuill, Brendan T
    • Wibowo, Johannes
    • Robbins, Bryant
    • Corcoran, Maureen K
    • Cooper, Deborah
    • Little Jr, Charles D
    • Cohen, Julie
    • Reed, Raymond
    • Holden, Kevin S
  • Publication Date: 2016-7


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 116p

Subject/Index Terms

Filing Info

  • Accession Number: 01608619
  • Record Type: Publication
  • Report/Paper Numbers: ERDC TR-16-10
  • Contract Numbers: 454633
  • Files: TRIS
  • Created Date: Aug 15 2016 4:32PM