流路の安定縦断形状に関する研究

Abstract

It may be one of the important problems in river and irrigation engineerings to estimatethe stable profiles of beds of rivers and irrigation canals with movable beds. In this paper, the stable profiles of the bed of a stream channel are defined under the conditions that, thefirst is the case when the tractive force of flow is critical and the other, the total load ofsediment transportation is constant at any section of a stream channel. The stable profilesfor flows upstream of debris barriers constructed in a wide, rectangular open channel, anopen channel with a gradually varied width and a prismatic open channel with a U-section, are considered theoretically by the analytical approach based on the both ideas of criticaltractive force and of continuity of sediment transportation, and compared with the experi-mental results. It is cleared from the comparison that the theoretical curves for the stableprofiles of beds are in good agreement with the experimental results, and the analyticalresults explain well the mechanism of establishing the stable profiles.In addition, applications of the above basic considerations to the field data for the pro-files of the river bed upstream of a debris barrier are described, and some problems in theapplication are briefly discussed.