NEW DEVELOPMENTS FOR EROSION CONTROL AT CULVERT OUTLETS

THE PROBLEM OF EROSION CONTROL AT CULVERT OUTLETS DEPENDS ON DISSIPATION OF KINETIC ENERGY IN THE HORIZONTAL DIRECTION, VERTICAL DIRECTION, OR COMBINATION OF BOTH DIRECTIONS. DISSIPATION OF KINETIC ENERGY MAY BE CONTROLLED IN THE VERTICAL DIRECTION BY USE OF A PRE-SHAPED ARMORPLATED STILLING BASIN. SYSTEMATIC EXPERIMENTS UPON THE RATE OF SCOUR AND SCOUR CONTROL IN AN ALLUVIAL BED BY A JET OF FREELY FALLING CLEAR WATER HAVE INDICATED SEVERAL ESSENTIAL FACTS. (1) A GRADED GRAVEL HAS PROVEN TO BE EXTREMELY EFFECTIVE AS PROTECTION AGAINST EROSION FROM HIGH-VELOCITY FLOW AND WAVES. IT IS IMPORTANT, HOWEVER, THAT THE GRAVEL BE GRADED SO THAT THE LARGER SIZE MATERIAL IS PROTECTED FROM UNDERMINING BY THE SMALLER SIZE MATERIAL UNDERNEATH. THE MAXIMUM SIZE OF THE GRAVEL MATERIAL MUST BE SUFFICIENT TO RESIST MOVEMENT FROM THE STILLING BASIN. (2) WAVE ACTION AND STANDING EDDIES AT CULVERT OUTLETS ARE TWO IMPORTANT FACTORS IN CAUSING EROSION OF ALLUVIAL BANKS. AN INCREASE IN CHANNEL WIDTH NEAR THE CULVERT OUTLET CAUSES AN INCREASE IN THE RATE OF SCOUR. (3) ARMORPLATE PROTECTION MUST BE PROVIDED TO THE CHANNEL BANKS WITHIN THE STILLING BASIN AREA TO PROVIDE PROTECTION FROM WAVES AND EDDIES. UNDER THE LABORATORY TEST CONDITIONS THE CHARACTERISTICS OF A STANDARD PRE-SHAPED STILLING BASIN ARE GIVEN. FOR THE LABORATORY CONDITIONS A MINIMUM OF 10 PERCENT ARMORPLATE BASED ON THE VOLUME OF SCOUR HOLE AT ONE HOUR OF SCOUR EFFECTIVELY CONTROLLED THE EROSION PROCESS. /AUTHOR/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/286/286-003.pdf
• Supplemental Notes:
  • No 286, pp 22-31, 7 FIG, 7 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
• Authors:
  • Smith, George L
  • Hallmark, Dasel E
• Conference:
  • 39th Annual Meeting of the Highway Research Board
  • Location: Washington DC, United States
  • Date: 1960-1-11 to 1960-1-15
• Publication Date: 1960

Media Info

• Monograph Title: Drainage structures: design and performance, 1960
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 286
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Alluvium; Culverts; Dissipation; Eddies; Erosion control; Gravel; Kinetic energy; Scour; Stilling basins; Wave motion
• Uncontrolled Terms: Outlets
• Old TRIS Terms: Wave action
• Subject Areas: Bridges and other structures; Energy; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00204164
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Apr 28 1994 12:00AM