山地灾害与地表过程重点实验室知识库

黏性泥石流是泥石流中最常见且破坏性最大的一类,测量其垂向流速分布是检验泥石流运动模型的有效手段。利用泥石流原状堆积物中10 mm以下部分模拟黏性泥石流,开展了7组流槽试验,对冲击力的垂向分布和泥深进行测量,根据冲击力的垂向分布反算得到流速的垂向分布。结果显示试验中黏性泥石流的流速分布特征与一般流体相似,且能够通过宾汉模型描述。揭示了通过测量冲击力分析黏性泥石流流速的可行性,但是研究结论需要通过对天然泥石流的冲击力测量进一步检验。

Viscous debris flow is the most common and serious destructive type among all kinds of debris flows. Measurement of its vertical velocity distribution is essential for testing debris flow models. In this study 7 flume tests were conducted to measure the vertical distribution of the impact force and flow depth of viscous debris flows,in which the experimental material was collected from natural debris flow deposit and was sieved by a 10 mm mesh screen. The vertical velocity distribution was obtained using the relationship between the impact force and velocity. Results show that the velocity of viscous debris flow changes with flow depth as other fluids. It means velocity increases with depth while shear rate shows an opposite trend. Moreover,the velocity distribution can be explained well by the Bingham model. This study reveals the availability of deriving velocity distribution by impact force measurement. However,further work should be conducted in natural debris flow gullies to verify these conclusions.