Methodology for calculating shear stress in a meandering channel
Date
2010
Authors
Sin, Kyung-Seop, author
Thornton, Christopher I., advisor
Julien, Pierre Y., committee member
Wohl, Ellen E., 1962-, committee member
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Abstract
Shear stress in meandering channels is the key parameter to predict bank erosion and bend migration. A representative study reach of the Rio Grande River in central New Mexico has been modeled in the Hydraulics Laboratory at CSU. To determine the shear stress distribution in a meandering channel, the large scale (1:12) physical modeling study was conducted in the following phases: 1) model construction 2) data collection 3) data analysis, and 4) conclusion and technical recommendations. Data of flow depth, flow velocity in three velocity components (Vx, Vy and Vz) and bed shear stress using a Preston tube were collected in the laboratory. According to the laboratory data analysis, shear stress from a Preston tube is the most appropriate shear stress calculation method. In case of the Preston tube, data collection was performed directly on the surface of the channel. Other shear stress calculation methods were based on ADV (Acoustic Doppler Velocity) data that were not collected directly on the bed surface. Therefore, the shear stress determined from ADV measurements was underestimated. Additionally, Kb (the ratio of maximum shear stress to average shear stress) plots were generated. Finally, the envelope equation for Kb from the Preston tube measurements was selected as the most appropriate equation to design meandering channels.
Description
Rights Access
Subject
shear stress
Rozovskii
Reynolds Shear
Preston tube
meandering channel
ADV
Shear strength of soils -- Testing
River channels
Erosion