Accession Number:

ADA101389

Title:

Stream Channel Stability. Appendix D. Bank Stability and Bank Material Properties in the Bluffline Streams of Northwest Mississippi,

Descriptive Note:

Corporate Author:

SOIL CONSERVATION SERVICE OXFORD MS SEDIMENTATION LAB

Report Date:

1981-04-01

Pagination or Media Count:

259.0

Abstract:

This report describes the analyses of processes and mechanisms of streambank erosion in the bluff line streams of Northwest Mississippi. Bank instabilities occur as a result of general channel degradation by headcutting and as a result of local scouring at the outerbank in bendways. Bank retreat takes place primarily by mass failures of overheightened and oversteepened banks. Failures are usually associated with the development of extensive tension cracks behind the bank and follow periods of heavy precipitation that maximize the bank material weight and minimize its strength. Slope stability analyses can be used to assess the stability of streambanks and to predict limiting values for the bank height and slope angle. In this report, the limit analysis for a log spiral toe failure is used. This requires data on the distribution and strength properties of the bank materials. These data were obtained from a borehole survey of bank stratigraphy and from in situ and laboratory strength tests. The accuracy of the stability analysis was tested using field observations of bank geometry. The tests indicated a good degree of success and this suggests that the analysis can be used as an aid in redesigning unstable banks with confidence. Author

Subject Categories:

  • Soil Mechanics
  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE