基于φ值粒度成分分析的泥石流动力特性

Dynmic Characteristics of Debris Flow Based on the Granularmetric Analysis of the Value of φ

为了更准确地预测乌东德水电站库区方山果沟泥石流的动力特性,首先采用概率累积曲线法对沟口堆积颗粒进行沉积环境的定性判断,然后采用图算粒度参数法对泥石流堆积物进行分析,并对泥石流的动力特性进行初步的定性判断,最后根据堆积颗粒受力分析结合初步的动力特性的定性判断结果建立固体颗粒的力平衡方程。通过对方山果沟泥石流堆积物进行分析,得出方山果泥石流沟具有以下动力特征:方山果沟泥石流堆积物以碎石为主,分选很差;在搬运能力极强的重力斜坡作用下以推移、滚动搬运的方式为主。在此基础上计算得到方山果沟泥石流流速ub=8.67m/s。

The authors predicted the dynamic characteristics of the debris flow.First,the granularmetric analysis was carried out and the qualitative judgment of the sedimentary environment was recognized.Then the granularmetric analysis on the accumulation zone of the debris flow was accomplished with the graphic method and the preliminary judgment of the dynamic characteristics was described.Finally,the force balance equation of the grain during the debris motion process was setup.The features of the debris flow accumulation zone of Fangshanguo along the Jinshajiang river was analyzed and conclusions were come out： the debris flow is composed of the gravel generally and poor in sorting,it made with the use of pulling and rolling of the gravity slope.Base on it,the velocity of Fangshanguo gully was calculated as ub=8.67 m/s.