Establish Guidance for Soils Properties-Based Prediction of Meander Migration Rate

Project Description

Because the main channel of a river will migrate and rework its flood plain from time to time, accurate predictions of future river locations are needed to protect and plan for highway bridges and other near-bank structures. This study was conducted to develop a method for estimating river migration distances and forecasting the future location of rivers.

Researchers conducted a literature review, a study of case histories, a three-dimensional numerical simulation to depict flow velocity fields and shear stress distributions, and very large-scale flume tests were conducted with two different soils (sand and clay) to represent the natural river processes.

Prediction of river meandering migration is very complex. Simple procedures are quite inaccurate, and the time-step extrapolation method is unable to accommodate future changes in soil and flow conditions. The numerical simulation in this project indicated that the maximum velocity and the maximum shear stress switch from one bank to the other in a curved bend. The flume tests and the case histories showed that there is a limit to the migration process and that there is a maximum migration distance.

The most important parameters affecting maximum migration distance are the channel radius to width ratio, the bend angle, flow Froude number and soil properties of the channel bank. Migration in clay is much slower than in sand, and maximum migration distance is a function of the critical velocity or the critical shear stress of the soil.

Project Publications

Establish Guidance for Soils Properties-Based Prediction of Meander Migration Rate 0-4378-1

Establish Guidance for Soils Properties-Based Prediction of Meander Migration Rate 0-4378-S

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