EVALUATION OF FLOOD RISK FACTORS IN THE DESIGN OF HIGHWAY STREAM CROSSINGS. VOLUME III. FINITE ELEMENT MODEL FOR BRIDGE BACKWATER COMPUTATION

A mathematical model describing the steady, two-dimensional subcritical flow in wide, heavily vegetated flood plains of bridge waterways has been developed using the finite element method of numerical analysis. The basic fluid equations comprising the model consist of the phenomenologic motion equations and the continuity equation, which are solved simultaneously by numerical methods to yield the spatial distribution of water surface elevations and velocities within the flow region for prescribing boundary conditions. The model simulates flow characteristics of arbitrary geometry. Hydraulic computations for various highway stream crossing orientations can be performed by the model. The model also simulates flow overtopping roadway embankments and performs hydraulic computations for a series of bridges across a stream valley without requiring prior assumption of the flow distribution for each bridge opening. The model has been tested for two example problems: a field site near Laurel, Mississippi, and for hydraulic flume data. In both examples good agreement between the model and the observed data was demonstrated.

• Supplemental Notes:
  • See also Volume 1, PB-244486.
• Corporate Authors:

  Water Resources Engineers, Incorporated

  8001 Forbes Place
  Springfield, VA  United States  22151

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Tseng, M T
• Publication Date: 1975-4

Media Info

• Pagination: 184 p.

Subject/Index Terms

• TRT Terms: Backwaters; Bridge design; Bridge waterways; Bridges; Channel flow; Channels (Waterways); Computer programs; Embankments; Finite element method; Flood plains; Floods; Flow; Flow fields; Highway bridges; Mathematical models; Risk analysis; Runoff; Streamflow; Streams; Structural design; Watersheds
• Uncontrolled Terms: Open channel flow
• Old TRIS Terms: Finite elements
• Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00137411
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: FHWA-RD-75- 53 Final Rpt., WRE-20810
• Contract Numbers: DOT-FH-11-7669
• Files: TRIS, USDOT
• Created Date: Sep 16 1977 12:00AM