A Better Design for Box Culverts?
This article explores how the Federal Highway Administration (FHWA) and the South Dakota Department of Transportation (SDDOT) collaborated to study the affects of inlet geometry on water flow in cast-in-place and precast structures such as box culverts. The FHWA-SDDOT research project, "Effects of Inlet Geometry on Flow Capacity of Single and Multiple Barrel Box Culverts," examined the coefficients for straight and flared inlets. The researchers conducted nearly 700 tests at the Turner-Fairbank Highway Research Center (TFHRC) Hydraulics Laboratory. Among the results were that there is almost no gain to edge bevel shapes for unsubmerged inlet control flow since the top edge with the primary bevel is not exposed to the flow. The following are among the significant findings: (1) Based on the particle image velocimetry (PIV) flow visualization technique developed at the TFHRC laboratory, the researchers determined that the optimum edge treatment for the crown of a culvert is a rounded radius of 203 millimeters (8 inches). This is the full thickness of the crown for the models tested. (2) There was a distinct difference in performance between square-edged crowns, beveled crowns, and rounded crowns for box culvert models with straight wingwalls under submerged conditions. (3) Multiple barrels had a slight but negligible hydraulic advantage over single-opening culverts for the inlet tests. Researchers noted that highway agencies seldom design for headwater depths greater than 1.5 times the culvert height. (4) Wide span-to-rise models acted similarly to multiple barrels, except where there was a slight hydraulic disadvantage in the coefficients for the wide-span models compared to the 1:1 span-to-rise models for both the inlet control tests and the outlet control tests. (5) No hydraulic advantage or disadvantage to extending the inner walls of multiple-barrel culverts onto the apron were found. (6) Skewed headwalls were found to have a detrimental effect on culvert hydraulics. Data from this study will be incorporated into current hydraulic design software, and as such, box culvert designs should become more efficient and cost-effective soon.
- Record URL:
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/oclc/1586080
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Authors:
- Kerenyi, Kornel
- Jones, J Sterling
- Phillips, Richard
- Oien, Paul
- Publication Date: 2005-9
Language
- English
Media Info
- Media Type: Print
- Features: Illustrations; Photos;
- Pagination: pp. 46-52
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Serial:
- Public Roads
- Volume: 69
- Issue Number: 2
- Publisher: Federal Highway Administration
- ISSN: 0033-3735
- Serial URL: https://www.fhwa.dot.gov/publications/publicroads/
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Publication flags:
Open Access (libre)
Subject/Index Terms
- TRT Terms: Box culverts; Cast in place structures; Coefficients; Culvert inlets; Flow visualization; Geometry; Hydraulics; Precast concrete
- Identifier Terms: Turner-Fairbank Highway Research Center
- Uncontrolled Terms: Collaborative research teams; Flow capacity; Headwalls; Hydraulic design; Particle image velocimetry
- Subject Areas: Bridges and other structures; Construction; Highways; I53: Construction of Bridges and Retaining Walls;
Filing Info
- Accession Number: 01011005
- Record Type: Publication
- Files: TRIS, ATRI
- Created Date: Dec 2 2005 11:18AM