以非均质泥石流为研究对象,通过实施云南东川蒋家沟泥石流堆积过程现场模拟实验,首先分析非均质泥石流堆积物颗粒级配组成的平面变化特点,即容重较低的稀性泥石流堆积扇两侧及前缘细颗粒较多,而容重较高的黏性泥石流堆积扇的两侧及前缘粗颗粒较多,并得出非均质泥石流堆积物中值粒径随泥石流容重减小而降低的结果;在此基础上,进一步分析泥石流堆积物垂向粒序分布特征,结果表明蒋家沟泥石流容重较小时泥石流堆积物颗粒垂向呈现正粒序分布,否则呈现反粒序分布或混杂粒序分布。本文研究成果对下一阶段建立泥石流堆积动力学模型及预测堆积成灾规模奠定了基础。
As a subject of non-homogeneous debris flow, according to the field experimental resuhs carried out at Jiangjia Gully, Yunnan Province, it has been indicated by our analysis that the plane grain size distribution properties of the debris flow depositing materials, such as, depositing more fine particle at two sides and front of debris flow with less unit weight and more coarse particle at two sides and the front of debris flow with more unit weight. Furthermore, the medium diameter for non-homogeneous debris flow is less with deceasing of unit weight. It shows that the vertical grain order distribution characteristics for the non-homogeneous debris flow is divided by the unit weight of 2.234t/m3, less than this value the order distribution of deposition will appear obverse graded bedding, otherwise behaviors reverse graded bedding or mixed grain bedding. Such results have laid the groundwork for establishing the dynamically deposited model and forecasting the scale of deposition disaster for non-homogeneous debris flow.