汶川县七盘沟泥石流斜坡物源启动模式及动储量预测研究

发布时间：2018-03-12 10:18

本文选题：泥石流　切入点：斜坡物源　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：泥石流是山区多发且危害巨大的一类地质灾害,而物源条件是泥石流发生的基本条件,并且决定着泥石流的规模大小,对泥石流的治理工程设计也起到决定性的作用。其中,斜坡物源占据着泥石流物源的半壁江山,其形成和启动模式复杂,动储量计算困难。本文结合汶川县七盘沟泥石流研究了斜坡物源的类型、启动模式,并且在其基础上提出了动储量定量计算的方法,并给出了动储量的影响因素权重,主要研究内容和成果如下：(1)通过对七盘沟泥石流松散固体物源点的调查分析,将斜坡物源划分为崩塌堆积物源、滑坡堆积物源、坡面侵蚀物源和坡顶震裂物源四种类型,并分别分析了每类斜坡物源的特征。(2)在斜坡物源分类的基础上,对各类物源的启动模式进行了详细的分析,对于崩、滑堆积物源根据其所处位置不同划分为三类分别进行启动模式分析。(3)分析了泥石流的冲刷机制,并且推导出了泥石流的最大冲刷深度计算公式,在此基础上给出了崩、滑堆积物源动储量计算的两种方法：弧形滑面搜索法和边坡稳定角法。其中边坡稳定角法分别采用库伦理论和极限平衡理论推导出了破裂角的表达式。(4)对于坡面物源动储量的计算引用了RUSLE方程,给出了方程中包含的五个因子(降雨与径流侵蚀因子、土壤可侵蚀因子、坡长和坡度因子、植被覆盖因子、侵蚀控制因子)的计算方法,并给出了七盘沟坡面物源点P5根据此方法计算的实例。(5)利用几何分析的方法给出了坡顶震裂物源动储量的计算方法,并采用数值分析的方法利用FLAC3D软件对该种计算方法进行了验证。(6)采用层次分析法分析了影响斜坡物源动储量的11个因素,并依照各个因素的权重值将其划分为影响很大(10%),影响较大(5%),影响一般(5%)三个等级。
[Abstract]:Debris flow (debris flow) is a kind of geological hazard in mountainous area, and the source condition is the basic condition of debris flow, and it determines the scale of debris flow, and plays a decisive role in the design of debris flow control engineering. The slope source occupies half of the debris flow source, its formation and start-up model is complex, and the calculation of dynamic reserves is difficult. This paper studies the types of slope provenance and the starting mode of the debris flow in Qipangou, Wenchuan County, China. On the basis of it, the quantitative calculation method of dynamic reserves is put forward, and the weight of influencing factors of dynamic reserves is given. The main research contents and results are as follows: 1) through the investigation and analysis of the loose solid source points of debris flow in Qipangou, The slope provenance is divided into four types: collapse and accumulation source, landslide accumulation source, slope surface erosion source and slope top shock crack source, and the characteristics of each kind of slope material source are analyzed respectively based on the classification of slope provenance. The starting mode of all kinds of material sources is analyzed in detail. For avalanche and landslide, the debris flow scouring mechanism is analyzed according to the location of the debris flow, which is divided into three types respectively. The formula for calculating the maximum erosion depth of debris flow is derived, and on this basis, the collapse is given. There are two methods to calculate the source dynamic reserves of sliding deposits: the arc sliding surface search method and the slope stability angle method, in which the slope stability angle method is derived by the Coulomb theory and the limit equilibrium theory, respectively, and the expression of the fracture angle is derived from the Coulomb theory and the limit equilibrium theory. The calculation of the material source dynamic reserves is based on the RUSLE equation. The calculation method of five factors (rainfall and runoff erosion factor, soil erosion factor, slope length and slope factor, vegetation cover factor, erosion control factor) included in the equation is given. An example of the calculation of source point P5 on the slope surface of Qipangou according to this method is given. The method of calculating the dynamic reserves of the crack source on the top of the slope is given by using the method of geometric analysis. The numerical analysis method is used to verify the calculation method with FLAC3D software. The analytic hierarchy process (AHP) is used to analyze the 11 factors that affect the dynamic reserves of the slope source. According to the weight value of each factor, it is divided into three grades: the influence is very big, the influence is great, the influence is greater, and the influence is general.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.23

【引证文献】