Transport Of Sediment Mixtures Research Articles

Transport of Sediment Mixtures in Steady Flow with an Extra Contribution of Their Finest Fractions: Laboratory Tests and Modeling

This paper presents the results of experimental studies on the transport of water-sandy mixtures with the content of very fine non-cohesive fractions in steady flow. The flow and shear velocity measurements as well as the measurements of sediment amount in the trap and control area were conducted. A theoretical model of the vertical structure of both velocity and concentration of sediment non-cohesive fractions as well as vertical mixing and sorting is presented here for transport calculations. The interaction effects between fractions are included, especially the influence of fine fractions in the mixture on transport of coarser fractions. The model provides an agreement between measurements and calculations of transport rate and grain size distributions of poorly sorted mixtures within plus/minus a coefficient of two. Further, the present model is used for calculating the limited contribution of very fine fractions in sediment due to deficit of those fractions in the bed. Again, the compliance of the calculations of sediment transport according to measurements is achieved. The satisfactory agreement between the calculations of grain size distributions and measurements is also found.

Review of Hans Albert Einstein: His Life as a Pioneering Engineer by Robert Ettema and Cornelia F. MutelASCE Press, Reston, VA 20191; 2014; ISBN 9780784413302; 330 pp.; $65.00

Review of <i>Hans Albert Einstein: His Life as a Pioneering Engineer</i> by Robert Ettema and Cornelia F. MutelASCE Press, Reston, VA 20191; 2014; ISBN 9780784413302; 330 pp.; $65.00

Effect of Size Gradation on Transport of Sediment Mixtures

Total bed-material load computations for nonuniform sediment mixtures were evaluated for the commonly used Engelund and Hansen, Ackers and White, and Yang transport formulas. The results of sediment transport computations indicate considerable scatter is in bed-material load transport relations for nonuniform sediment mixtures. The analysis demonstrates that a single fixed size, such as D35 or D50, cannot reflect the presence of various size fractions on the transport of nonuniform sediment mixtures. A size gradation compensation factor incorporates the effect that the size distribution has on the transport of sediment mixtures. The size gradation compensation factor, Kg, which is a function of the geometric standard deviation, σg, of the bed material and the flow conditions, in conjunction with the D50 of the bed material yields an equivalent representative diameter, De. By including De in the Engelund and Hansen, Ackers and White, and Yang formulas, the agreement between computed and measured bed-materi...

Closure to “ Suspended Load Transport of Sediment Mixtures ” by Belle R. Samaga, Kittur G. Ranga Raju, and Ramchandra J. Garde (November 1986, Vol. 112, No. 11)

Closure to “ <i>Suspended Load Transport of Sediment Mixtures</i> ” by Belle R. Samaga, Kittur G. Ranga Raju, and Ramchandra J. Garde (November 1986, Vol. 112, No. 11)

Discussion of “ Suspended Load Transport of Sediment Mixtures ” by Belle R. Samaga, Kittur G. Ranga Raju, and Ramchandra J. Garde (November 1986, Vol. 112, No. 11)

Discussion of “ <i>Suspended Load Transport of Sediment Mixtures</i> ” by Belle R. Samaga, Kittur G. Ranga Raju, and Ramchandra J. Garde (November 1986, Vol. 112, No. 11)