DESIGN OF ROUGHNESS FOR ENERGY DISSIPATION IN HIGHWAY DRAINAGE CHUTES
A RECURRING NEED IN HYDRAULIC ENGINEERING IS A SIMPLE, RELIABLE METHOD FOR THE DISSIPATION OF EXCESS ENERGY IN STORM WATER FLOWING DOWN STEEP DRAINAGE CHANNELS. IN THE PAST, THIS PROBLEM HAS USUALLY BEEN HANDLED BY SOME FORM OF STILLING BASIN AT THE CHANNEL OUTLET. AN ALTERNATE METHOD THAT IS PRACTICAL IN MANY CASES IS THE PROVISION OF ROUGHNESS ELEMENTS IN THE CHANNEL ITSELF. SUCH ELEMENTS CAN BE DESIGNED TO PRODUCE THE PHENOMENON OF TUMBLING FLOW IN THE CHANNEL. THIS IS A CYCLICALLY UNIFORM FLOW CONSISTING OF A SERIES OF HYDRAULIC JUMPS AND OVERFALLS, WHICH ASSURES THAT THE CHANNEL OUTLET VELOCITY WILL NOT EXCEED THE KNOWN 'CRITICAL VELOCITY' FOR THE GIVEN DISCHARGE. LABORATORY AND FIELD STUDIES HAVE BEEN CONDUCTED AT THE VIRGINIA POLYTECHNIC INSTITUTE FOR THE PURPOSE OF DEVELOPING DESIGN CRITERIA FOR THIS METHOD OF ENERGY DISSIPATION. ON THE BASIS OF THESE TESTS, IT IS RECOMMENDED THAT EITHER TWO-DIMENSIONAL SQUARE ELEMENTS OR CUBICAL ELEMENTS BE USED. DESIGN EQUATIONS ARE PRESENTED ALONG WITH RECOMMENDATIONS FOR SPACING AND PLACEMENT OF THE ELEMENTS. /AUTHOR/
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Supplemental Notes:
- No 261, pp 25-37, 5 FIG, 15 REF. 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.
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Authors:
- Morris, H M
- Publication Date: 1969
Media Info
- Media Type: Digital/other
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Serial:
- Highway Research Record
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Cubes; Design; Dissipation; Ditches; Drainage; Equations; Hydraulic jump; Hydraulics; Location; Roughness; Spacing; Stilling basins; Velocity
- Uncontrolled Terms: Design criteria; Two dimensional
- Old TRIS Terms: Placement; Tumbling
- Subject Areas: Design; Energy; Highways; Hydraulics and Hydrology;
Filing Info
- Accession Number: 00204220
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Aug 4 1994 12:00AM