Thesis - Open Access
Master of Science (MS)
Sediment transport is a phenomenon which must -be taken into account when an engineering project includes or influences a natural channel. Most notable of these projects are reservoirs, river training structures and bridge piers. The useful life of a reservoir is directly the amount of sediment transported in a river. River training structures affect the acceleration of the flow and cause scour or deposition dependent on design. Bridge piers which are not properly designed can also cause the same accelerations causing deposition or, in a worst case, scour, threatening the pier and bridge. The design of earthen channels must take into account sediment transport. the channel below threshold cause transport. Transport with hydraulic equations in Designs are made to keep values of parameters which equations can also be used computer models of rivers to predict areas of scour and deposition. Many methods are available for transport calculations. These methods include Duboys, Einstein, Colby and Toffaleti, to name only a few. All methods use different types of analysis of the hydraulic data from the stream. In 1973, Ackers and White introduced a simple set of new equations which, in the words of the authors, "avoids refinements that may complicate the application without adding much to accuracy". These equations are to be used for uniform, noncohesive sediments. Since normal stream beds do not contain uniform gradations of sediment, attempts have been made to vary the Ackers White transport equations for use in transport calculations with a graded sediment: The most notable of these is the White and Day work at the Hydraulic Research Station (HRS) in Wallingford, England. This thesis is an attempt to modify the original Ackers - White equations to apply to graded as well as uniform sediments. Data was obtained from work done by White and Day. A computer program was used to generate parameters from this data. The threshold values for transport were calculated from actual transport data and used to generate a new curve for use in graded sediment transport calculations. The specific objectives of the project are as follows: 1) Modify the original Ackers - White equations to ·allow the use of size fractions to calculate the transport of graded sediments as well as uniform sediments. 2) Match calculated transport values to the original Ackers - White procedure and 3) Match calculated transport values to actual transport values for each size fraction.
Library of Congress Subject Headings
Number of Pages
South Dakota State University
No Copyright - United State
Lewandowski, Jeff A., "Modification of the Ackers and White Transport Equation to Permit Calculation by Size Fractions" (1985). Electronic Theses and Dissertations. 4285.