急勾配流れの抵抗と限界掃流力に関する研究

Abstract

We have discussed in this paper that Darcy-Weisbach's resistance coefiieientf should be a func-tion of d/h, u'*5/td and Nd2 and have made clear by some experiments the functional relationshipsbetween these parameters.Theoretical discussion for the initiation of motion of bed particles comes to the conclusion thatthe critical shear stress parameter 5, , which is known as Shields' parameter, must be modified for theeffects of steep slope. Some experimental results show that the modified Shields' parameter S., , isa function of relative roughness d/h. And if d/h increases, S, , will remarkably increase.An experimental formula of s, , , is proposed and the relationship is proved to be valid by thetheoretical discussion using the experimental results for the resistance law.