Theerawat Tangpanich creator Watanabe, Akira Chairperson Prida Thimakorn Co-Chaiperson Overbeek, Henk Jen Examination Committee Provincial Government of British Columbia Scholarship Donor text th Bangkok Asian Institute of Technology 1977 monographic eng

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98 p. The purpose of this study is to investigate the effect of non-uniformity of grain size on sediment discharge in a steady flow. Laboratory experiments have been conducted by using a recirculating flume, in which the graded sediments with a medium diameter of 0.50 mm and a geometric standard deviation of 2.23 have been placed. The suspended load, total load, flow discharge and the water surface slope have been measured for several different flow conditions. The grain-size distributions of transported sediments have also been measured by mechanical sieving method. The values of critical shear stress evaluated by two different methods based on the experimental data are compared with the previous studies by Straub and Shields, and the interaction effect between sediment fractions of different grain size is discussed. The values of sediment transport evaluated by the DuBoys' as well as Engelund and Hansen's formula show quite good agreements with the measured ones, while the Einstein's bed load function is concluded to give considerably smaller values. The sediment load is also evaluated for each grain size fraction, into which the total load is divided, by using the DuBoys ' formula, and is compared with the measured value. It is suggested that in the sediment mixture of non-uniform size, the coarse grains might tend to move more easily as compared with the uniform sediment of the same size, while the fine sediment might be obstructed to move and show smaller discharge. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand Thesis (M.Eng.) - Asian Institute of Technology, 1977 Sedimentation and deposition Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B22685 http://203.159.5.9/ait-thesis/detail.php?q=B22685 200198 20260818094946.0