Fish Passage in Large Culverts with Low Flows

A series of physical and numerical modeling runs were completed to support the development of a design procedure for characterizing the variation in velocity within non-embedded and embedded culverts. Physical modeling of symmetrical half-section circular culverts was conducted to provide data against which computational fluid dynamics (CFD) modeling could be validated. The initial CFD modeling featured two-phase numerical computations that successfully reproduced the physical modeling results. To further simplify, single-phase modeling and truncated single-phase modeling were evaluated with good results. For the embedded culvert runs, a successful strategy for representing natural bed material within the culvert was developed. Once the CFD modeling was validated by the physical modeling, the CFD modeling was used to analyze the full culvert cross-sections. Test matrices included CFD runs scaled up to larger culvert sizes. One series of runs maintained Froude number based scaling and one series tested larger sizes without the scaling constraint. The CFD runs and a velocity distribution model formed the basis of a proposed design methodology for determining the velocity distribution within a culvert cross-section. Using the 42 CFD runs for a 3-ft diameter culvert, the 5 parameters necessary for the velocity model were estimated. Then, based on geometric and hydraulic parameters available to a designer, relations were developed to estimate those parameters. The approach was successfully validated on CFD runs for 6-ft and 8-ft diameter culvert models. The proposed design procedure allows a designer to estimate the velocity throughout a cross-section. These data may be depth-averaged to provide a distribution of velocity and depth across the culvert cross-section that may be used to evaluate fish passage. Although developed for circular culverts, the parameters used in the method are such that the procedure should be applicable to rectangular and other shapes. Two design examples and an application guide are provided to illustrate the method and the required computations.

• Record URL:
  http://www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/14064/14064.pdf
• 
• Summary URL:
  http://www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/14064/index.cfm
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/35936
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/44394
• Corporate Authors:

  Genex Systems, LLC

  2 Eaton Street, Suite 603
  Hampton, VA  United States  23669

  Federal Highway Administration

  Turner-Fairbank Highway Research Center
  Office of Infrastructure Research and Development
  McLean, VA  United States  22101
• Authors:
  • Zhai, Yuan
  • Mohebbi, Amin
  • Kilgore, Roger
  • Xie, Zhaoding
  • Shen, Jerry
• Publication Date: 2014-8

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 138p

Subject/Index Terms

• TRT Terms: Culverts; Design; Fishes; Fluid dynamics; Hydraulics; Mathematical models; Scale models; Velocity
• Subject Areas: Bridges and other structures; Design; Environment; Highways; Hydraulics and Hydrology; I15: Environment; I26: Water Run-off - Freeze-thaw;

Filing Info

• Accession Number: 01541500
• Record Type: Publication
• Report/Paper Numbers: FHWA-HRT-14-064
• Contract Numbers: DTFH61-11-D-00010
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: Oct 21 2014 2:09PM