SCOUR AT BRIDGE PIERS-FIELD DATA FROM LOUISIANA FILES

Data from a total of 17 occurences of scour at seven bridge sites in Louisiana were collected, covering the following ranges: Pier width, 3.4-10.4 m; flow depth, 1.7 - 19.5 m; flow velocity, 0.46 - 1.8 m/s; Froude number, 0.067-0.189; scour depth, 3.4 - 10.4 m, and bed material median diameter, 0.008 - 0.06 mm. An analysis of the relative scour depth with respect to relative flow depth for flows with Froude numbers about 0.1 shows that the scour depth increases rapidly with an increase in flow depth when the relative flow depth is less than 0.5. The rate of increase then slows down to approach a constant value of 0.8 maximum as the relative flow depth approaches 1.3 and may tend to decrease very slightly as the relative flow depth increases further. For the data where the Froude numbers were about 0.1, Shen's formula II (2) yields the best agreement. Three of the other popular formulas - Laursen's, Shen's formula I and Neill's approximation of Laursen's design curve - tend to overpredict the scour, and three formulas - Ingles-Poona's, Ahmad's and Chitale's - tent to underpredict the scour for these low Froude numbers. (FHWA)

• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/75197
• Corporate Authors:

  Tye Engineering Company

  9614 Jomar Drive
  Fairfax, VA  United States  22030

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Chang, FFM
• Publication Date: 1980-1

Media Info

• Pagination: 34 p.

Subject/Index Terms

• TRT Terms: Bridge design; Bridge piers; Bridges; Depth; Erosion; Field studies; Flow; Flow fields; Froude number; Piers; Scour; Structural design; Structural piers; Velocity; Width
• Uncontrolled Terms: Field data
• Geographic Terms: Louisiana
• Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology; I26: Water Run-off - Freeze-thaw;

Filing Info

• Accession Number: 00316405
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-79-105 Final Rpt., FCP 35H1-222
• Contract Numbers: FHWA P.O. 8-3-0129
• Files: NTL, TRIS, USDOT
• Created Date: Feb 6 1981 12:00AM