泥石流的结构两相流模型:Ⅱ.应用

CONCEPTUAL TWO PHASE FLOW MODEL OF DEBRIS FLOW: Ⅱ. APPLICATION

本文应用泥石流的结构两相流模型对各类泥石流的运动机理进行探讨，并成功地解释了泥石流运动中的一系列特殊现象，如可能出现的颗粒浓度“上大下小”型分布、泥石流垂线速度的“反Ｓ”型分布、泥石流中颗粒脉动速度分布变化的特殊性、泥石流的输移特性以及在一定条件下出现的“流核”现象，等等。模型计算结果得到了实验资料的验证。

Based on the conceptual two phase flow model developed in the companion paper, applications of the model to the mechanism of various debris flows including muddy flow, water rock flow as well as the general debris flows are discussed in greater details in the present paper. Specific characteristics of debris flows are sumarized and theoretical explanations are given subsequently. Special attention is paid to the flow characteristics of debris flow with cohesionless particles in either mild or steep flumes since there are enough reliable measured data in this study field. Predictions for the specific particle concentration profile, velocity profile, fluctuation profile as well as the particle transport properties are made for both saturated and non saturated water rock flows. It is indicated that the saturated water rock flow occuring in the mild slope channel behaves more like the laminated flow does, with common particle concentration, fluctuation profiles as well as transport characteristics, but with typical particle velocity profiles different from those in sediment laden flows. However, the non saturated water rock flow occuring in the steep slope channel behaves more like the rapid granular flow, dominated by the collision among particles, and thus demostrate all kinds of special characteristics reported on the water rock debris flows. The maximum concentrations at the flow surface and other special behaviours are succesfully modeled. The predicted results are reasonably verified by the experimental results. It is also indicated that more characteristics of debris flows will be possible to be explained theoretically by using the conceptual model in case that the technology of measurements is improved in the near future.