2019 年 25 巻 p. 747-752
The shape of the non-spherical gravel plays an important role in the river bed structure and the sediment transport. However, it is general to treat gravel of non-spherical shapes as spheres. In this study, the method of determining the representative particle diameter of gravel was discussed based on the numerical movable-bed experiment using the non-spherical gravel of uniform size. First, the effect of the orientation and arrangement of bed gravel on the stability of the bed was analyzed, and it was clarified that the stable structure of the surface gravel is the imbrication. Next, the representative length of the non-spherical gravel was examined from the difference of the orientation and arrangement of the bed surface gravel. Then, the particle size distribution of the gravel on the bed surface was obtained. Finally, the sediment transport rate was calculated using the obtained particle size distribution, and the problem of the conventional sediment transport analysis was presented, and it was shown that determining the particle diameter of gravel was significant for the fluvial hydraulics.
