MATHEMATICAL MODEL FOR ESTIMATING SCOUR THROUGH BRIDGE CROSSINGS

Changes in bed level in alluvial channels are an important design consideration for bridge crossings. The general problem of scour at bridge crossings involves degradation, aggradation, and local scour. Three types of interrelated scour phenomena are found at bridges: (a) local scour caused by piers and abutments disturbing the flow, forming vortices and eddies; (b) scour due to contraction of the flow at the crossing, causing increased velocities in the contracted width; and (c) degradation or aggradation of a stream channel over relatively long reaches and over a long time due to bed-level controls, changes in sediment supply, and changes in river form. A model of these scour phenomena has been developed by Simons, Li & Associates using a known-discharge sediment-routing procedure called HEC2SR. The model determines scour in reaches of a river system based on available sediment supply, local hydraulic conditions, and sediment-transport capacity. Hydraulic conditions for the river are determined using the U.S. Army Corps of Engineers HEC-2 computer program. The procedure was designed to take advantage of the bridge hydraulic modeling routines in HEC-2. Output from the modeling procedure includes detailed hydraulic and sediment-transport data as well as cross-sectional information. Application of the model to a complex site is shown. The analysis procedure provides important information pertinent to the design of river-training measures used in conjunction with bridge crossings. (Author)

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1984/950/950v2-028.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=MATHEMATICAL+MODEL+FOR+ESTIMATING+SCOUR+THROUGH+BRIDGE+CROSSINGS&author=D.+Simons&author=R.+Li&author=G.+Cotton&publication_year=1984
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• Supplemental Notes:
  • This paper appeared in Transportation Research Record Number 950, Volume 2, Second Bridge Engineering Conference, conducted by the Transportation Research Board and the Federal Highway Administration, September 24-26, 1984. Publication of this paper sponsored by Committee on Hydrology, Hydraulics, and Water Quality. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Simons, Daryl B
  • Li, Ruh-Ming
  • Cotton, George K
• Conference:
  • Bridge Engineering Conference, 2nd, 1984, Washington, DC, USA
• Publication Date: 1984

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 244-251
• Monograph Title: Second bridge engineering conference. volumes 1 and 2
• Serial:
  • Transportation Research Record
  • Issue Number: 950
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Bridge abutments; Bridge design; Bridge piers; Bridges; Hydraulics; Mathematical models; Scour; Sediments; Structural design
• Subject Areas: Bridges and other structures; Design; Highways; Hydraulics and Hydrology; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00390836
• Record Type: Publication
• ISBN: 03090036593
• Files: TRIS, TRB
• Created Date: Dec 30 1984 12:00AM