CONCENTRATION AND VELOCITY OF DEBRIS FLOWS  

作　　者：Xiangjun FEI Peng CUI Yong LI 

机构地区：[1]Tsinghua University,Beijing,100084,China,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences & Ministry of Water Conservancy,Chengdu,610041,China,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences & Mini

出　　处：《International Journal of Sediment Research》2002年第3期233-243,共11页国际泥沙研究（英文版）

基　　金：This research is supported by the National Science Foundation;NSF grant No.49831010.

摘　　要：Debris flows in nature generally fall into three groups distinct in their grain composition: water-stone flow, or sub-viscous debris flow, dominated by coarse grains; muddy flow, dominated by fine grains; and viscous debris flow composed of grains in large range. Liquid-phase velocity and sedimentary delivery resistance of sub-viscous debris flow have been discussed based on the composition characters of sub- and high-viscous debris flows. It is revealed that the presence of fine grains plays a vital role in affecting resistance and average velocity, particularly when the volume fraction of grains in the flow is relatively high, i.e. Sv > 0.45. Grain-size distribution of viscous debris flow is characterized by a bimodal curve, which explains the properties like high density and low resistance gradient of debris flows. A calculation formula is finally put forward, which has to some extent overcome locality limits and achieved a good agreement with the field observations of debris flows in Southwest China.Debris flows in nature generally fall into three groups distinct in their grain composition: water-stone flow, or sub-viscous debris flow, dominated by coarse grains; muddy flow, dominated by fine grains; and viscous debris flow composed of grains in large range. Liquid-phase velocity and sedimentary delivery resistance of sub-viscous debris flow have been discussed based on the composition characters of sub- and high-viscous debris flows. It is revealed that the presence of fine grains plays a vital role in affecting resistance and average velocity, particularly when the volume fraction of grains in the flow is relatively high, i.e. Sv > 0.45. Grain-size distribution of viscous debris flow is characterized by a bimodal curve, which explains the properties like high density and low resistance gradient of debris flows. A calculation formula is finally put forward, which has to some extent overcome locality limits and achieved a good agreement with the field observations of debris flows in Southwest China.

关 键 词：Sub-viscous debris flow Viscous debris flow Grain composition CONCENTRATION VELOCITY 

分 类 号：TV142[水利工程—水力学及河流动力学]