A SEDIMENT DISCHARGE FORMULA FOR VARIOUS TYPES OF SEDIMENT TRANSPORT IN A STEEP OPEN CHANNEL

在陡峭明渠的动床上，泥沙运动可分为四种主要类型及其两种中间类型：床面悬移质输沙型、泥石流泥石流输沙型和推移质泥石流过渡型。Hirano和Hashimoto(1995,1997)提出的高含沙水流模型可以适用于陡峭明渠中各种输沙水流。流动模型由颗粒层和惯性层组成，前者以晶间应力为主，后者以惯性力为主。在水流模型的基础上，Hirano和Hashimoto(1996,1998)推导了输沙公式。文中还将输沙量公式与试验结果进行了比较，并与其他公式进行了比较。由Hirano和Hashimoto(1996,1998)推导的输沙公式计算结果与试验结果吻合较好。

Four main types of sediment transport and their two intermediate types can be distinguished on movable bed in a steep open channel ; those are bed and suspended load types, debris and mud flow types, and intermediate types between bed load and debris flow types. The flow model for hyperconcentrated sand-water mixtures proposed by Hirano and Hashimoto (1995, 1997) can be applied to all types of flows with sediment transport in a steep open channel. The flow model consists of granular and inertial layers ; the intergranular stresses play major role in the former layer and inertial forces in the latter layer. On the basis of the flow model, sediment discharge formulas have been derived by Hirano and Hashimoto (1996, 1998 ). In the present study the sediment discharge formulas are compared with the experimental results and also with the other formulas. The calculation of sediment discharge formulas derived by Hirano and Hashimoto (1996, 1998 ) shows good agreement with experimental results.