IMHE OpenIR  > 成都山地所知识仓储(2009年以前)
Thesis Advisor崔鹏
Degree Grantor中国科学院成都山地灾害与环境研究所
Place of Conferral成都
Degree Name硕士
Degree Discipline自然地理学
Keyword泥石流 阵性波 波状运动 浅水波 标志网格法
Abstract阵性流运动是粘性泥石流在自然界中一种比较常见的运动方式。本文从水波动理论的角度出发把这种龙头一龙身一龙尾阵次交替的运动作为一种阵性波状运动来进行研究。文章的前一部分依据大量野外观测和实验资料详细考察了泥石流波状运动的波形、波速和周期等在空间和时间上的变化特征,得到一些新的结果 l)提出泥石流龙头是以拉伸,前倾,下落,而后揭起的滚动方式向前运动的;2)把泥石流龙身部分的速度剖面划分成缓变区、陡变区和塞流区三个部分;3)泥石流的阵性流是一种急流,只向下游传播;4)除间断性以外,泥石流波状运动还表现为非周期性;5)将波状运动分为三类:涌波、滚动短波、滚动长波。文章的后一部分把泥石流的运动简化为浅水波运动,然后结合标志网格法,并采用反映特征传播性质的迎风差分格式对不同条件下的一个概化的泥石流运动问题进行数值求解。计算的结果表明:1)即使上游为连续的流量条件,泥石流在运动过程中也会自发生成阵性波;2)在某些条件下,如底面的坡度较大或者底面糙率为零,泥石流的波状运动随时间是不稳定性,波高和波速都会越来越大;3)如果底面坡度等于零,则没有阵性波出现。结果初步映证了泥石流的波状运动不仅和底面坡度、糙率有关,而且有其深刻的内在机理。这种内在机理集中反映在表征泥石流浅流运动的浅水波方程的非线性和泥石流的非牛顿体的流变模式中。
Other Abstract

Intennittent flow, a common patterm of movement of víscous debris flows occurring in nature, is viewed as a wave phenomenon in the paper. According to plenty of field investigation and experiment infonnation, the first part of this paper discussed in detail temporal and spatial characteristics of wave shape, velocity, period, etc. The
wave decomposítion, overlap and movement way are also described deeply. Then
some new conclusions are obtained:
1) the wave front moves forward in a scrol1ing way on the bed with thin slurry of debris flows;
2) the velocity profile of body of debris flows is divided into three sections: gent1e flow, steep flow and plug flow;
3) the intennittent flow is super-critical flow that only propagates towards downstream;
4) the wave is proved to be non-periodic by the periodic analysis of intermittent time;
5) the wave movement is classified into three types: ground swell, short roll wave, long roll wave.
In the second part the movement is reduced to a kínd of shallow flow wave because it has three features: gravity driving, free surface, the ratio of flow depth and wavelength less than 0.4. After that MAC(marker and cell) method

is applied to solve a generalized two-dimensional problem of debris flows and the upwind scheme is adopted in order to reflect hyperbolic characteristic of the equation. The results of computation indicate:
1) the intennittent wave can appear spontaneously even if the upstream discharge is contmuous;
2) As time lapses the wave is unstable under some certain conditíons such as
large slope or zero roughness;
3) ifthe slope is equal to zero the íntennittent wave would not occur.
So the wave movement is relevant to slope and roughness, and there are some intrinsic mechanisms behind the phenomena. We think the mechanisms lie in nonlinear shal10w wave equation and non-Newtonian fluid model.

Document Type学位论文
Recommended Citation
GB/T 7714
胡凯衡. 泥石流的波状运动研究[D]. 成都. 中国科学院成都山地灾害与环境研究所,2002.
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