EVALUATION OF FLOOD RISK FACTORS IN THE DESIGN OF HIGHWAY STREAM CROSSINGS. VOLUME II--ANALYSIS OF BRIDGE BACKWATER EXPERIMENTS
This report presents the results of a series of experiments carried out using a large scale physical model of backwater caused by highway stream crossings of wide, heavily-vegetated flood plains. Variables studied included wingwall and spillthrough abutements, spur dikes, prototype bridge openings between 100 and 1100 ft and prototype flows between 8,000 and 36,000 cfs. An important aspect of these experiments was the use of large scale roughness elements protruding the free surface to provide the necessary ranges of roughness to simulate prototype conditions. Five combinations of roughness densities in patterns were tested in the course of experimentation. Primary emphasis was on crossings normal to flow; however, eccentric and skewed crossings were also tested. Results of the study included an analysis of the sensitivity of water surface elevation to the principal variables, quantification of both the local and height of the maximum backwater, and data for possible future study and modification of existing backwater methods. /Author/
- This report was sponsored by the Offices of Research and Development, Federal Highway Administration, U.S. Department of Transportation. See also Volume 1 dated Aug 74, PB-244486.
Water Resources Engineers, Incorporated8001 Forbes Place
Springfield, VA United States 22151
- Knepp, A J
- Subinski, R P
- Tseng, M T
- Publication Date: 1977-4
- Features: Appendices; Figures; References; Tables;
- Pagination: 182 p.
- TRT Terms: Abutments; Backwaters; Bridge design; Bridges; Flood plains; Floods; Fluid dynamics; Mathematical models; Risk analysis; Roughness; Runoff; Sensitivity; Simulation; Spur dikes; Streams; Structural design; Watersheds
- Uncontrolled Terms: Models; Water surface profiles
- Subject Areas: Bridges and other structures; Highways; Hydraulics and Hydrology;
- Accession Number: 00168387
- Record Type: Publication
- Source Agency: Federal Highway Administration
- Report/Paper Numbers: FHWA-RD-75- 52 Final Rpt.
- Contract Numbers: DOT-FH-11-7669
- Files: NTIS, TRIS, USDOT
- Created Date: Feb 16 1978 12:00AM