| 题名 | 泥石流物质演化特征 |
| 作者 | 王保亮 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 北京 |
| 导师 | 李泳 |
| 关键词 | 泥石流 标度分布 细颗粒迁移 随机序列 流变特性 |
| 其他题名 | The evolution characters of debris flow particles |
| 学位专业 | 岩土工程 |
| 中文摘要 | 泥石流所含土体颗粒满足标度分布方程：P(D)=CD-μexp（-D/Dc），土体的性质可以用(μ，Dc)两个参数来描述。本文以标度分布方程为基础，围绕泥石流颗粒演化，系统地研究了源地土体细颗粒迁移变化规律、土体坍塌破坏规律以及泥石流运动过程中颗粒混合变化时的颗分参数变化特征，得出以下主要结论： (1) 水在土体中的入渗过程，并不单纯是水的渗透问题，而且还伴随着细颗粒的迁移变化。源地土体颗粒分布的多样性，可能导致水的渗流路径不同。水槽实验表明，在堆积体垂直方向上，细颗粒随降雨入渗向下迁移；在水平方向上，细颗粒随坡面产流向下运移。即细颗粒的迁移路径与降雨的渗透路径呈现出一致性。 (2) 堆积体内细颗粒的总运移量随降雨强度和降雨历时的不同而不同，在相同降雨时间下，堆积体细颗粒迁移量随降雨强度的增大呈现出抛物线型先减小后增大的变化趋势。 (3) 泥石流源地坡面土体的颗粒分布并不是处处相同的，通常会表现出很大的随机性，土体的坍塌破坏在时间和空间上也会呈现出一定的随机性，破坏后土体颗粒分布得到重新组合，这种颗粒组成的变化，可以用（μ, Dc）变化的时间序列来描述。 (4) 泥石流颗粒分布的变化可以导致密度的改变，密度ρ与颗分参数μ、Dc存在着ρ=1.26μ-0.132+0.049Dc0.443这样一种函数关系，我们可以利用这种关系，结合源地土体坍塌破坏时产生的(μ，Dc)的时间序列，推测可能产生泥石流密度等流变特性的变化特征。 |
| 英文摘要 | The soil grain size of source area are fitted perfectly with a general form of grain size distribution: P(D) = CD – μ exp(– D/Dc), we can use the different distribution parameters (μ, Dc) to describe different soil composition, This study was based on the scaling distribution for grain composition of debris flow, centered on debris flow particle evolution, fine particles character of transporting, character of soil collapse and dynamic change of distribution parameters (μ, Dc) during the debris flow process were studied. The main results are as follows (1) The water infiltration process in the soil, is not only the penetration of water, but also accompanied by the fine particles migration. The diversity of soil particle size distribution of the source area, may lead to different water seepage path. What we can learn from the Flume experience is that, in vertical direction, the fine particles downward with the migration of rainfall infiltration, in the horizontal direction, the fine particles downward with the overland flow movement, seepage path and precipitation of fine particles are very similar. (2) fine particles of the total amount of migration varies with the rainfall intensity and rainfall duration, under certain rainfall time, the change of fine particles First decrease and then increase with the increase of rainfall intensity. (3) The source slope of soil particle size distribution is not the same everywhere, but shows great randomness, the collapse of the soil in time and space also shows certain randomness. After collapse, soil particle size distribution were recombination, this kind of change can be descripted using the dynamic change of (μ，Dc). (4) The change of grain size distribution can lead to the change of density, density ρ and distribution parameters (μ, Dc) has a function relationship as ρ=1.26μ-0.132+0.049Dc0.443, we can use this relationship and the dynamic change of (μ，Dc) to surmise the rheological characteristics of potential debris flow. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/14128]  |
| 专题 | 成都山地灾害与环境研究所_山地灾害与地表过程重点实验室 |
| 作者单位 | 中国科学院成都山地灾害与环境研究所 |
| 推荐引用方式 GB/T 7714 | 王保亮. 泥石流物质演化特征[D]. 北京. 中国科学院大学. 2015. |
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