Toe Scour and Bank Protection Using Launchable Stone.
Abstract
An empirical method for scour depth estimation is developed based on radius/width and aspect ratio. The thickness of the before-launch section controls the rate at which rock is released and should be 2.5 to 4.0 times the thickness of the bank protection revetment Tau for gradual scour and 2.5 to 3.0 Tau for rapid scour found in impinged flow environments. Riprap size for gradual scour is the same for both launched riprap and riprap placed by standard construction methods. Stone volume requirements are presented as a function of scour depth and whether the launch section is placed in the dry or underwater. Gradations having D85/D15 > 2 are recommended for launched riprap sections to prevent leaching of bank material through the launched riprap. (MM)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1995
- Accession Number
- ADA302130
Entities
People
- Douglas M. White
- Stephen T. Maynord