无黏性岩石碎屑流的运动特征及影响因素研究

发布时间：2018-03-19 21:08

本文选题：高速滑坡　切入点：岩石碎屑流　出处：《西华大学》2017年硕士论文　论文类型：学位论文

【摘要】：因高速远程滑坡岩石碎屑流具有流动性强、滑动速度快、波及范围广以及滑坡启动时的突发性和其运动路径的不可预测性等众多特点,使得滑坡发生地人民的生命财产受到巨大的威胁。目前国内外对这种高速远程滑坡岩石碎屑流的研究成果颇丰,但是由于其发生前的早期识别能力较差,使得不能及时、安全的疏散人员,致使这种灾难性事件引起的死伤情况仍不断上演着。因此,对这种高速远程滑坡碎屑流的堆积物堆积规律以及其高速远程的影响因素研究具有重大的现实意义。本文对高速远程滑坡岩石碎屑流进行室内小尺度物理模型实验,试图找出其高速远程的影响因素以及岩石碎屑流发生之后的堆积物分布规律。再利用PFC3D离散元分析软件对岩石碎屑颗粒滑坡进行模拟,分析滑坡体运行速度、距离的变化情况,并与室内物理模型实验结果进行比较。再通过对高速远程滑坡岩石碎屑流的理论研究,推导出滑坡水平运动距离的计算方程式,为以后发生的高速远程滑坡碎屑流的水平运动距离预测提供理论上的依据。论文取得的主要成果与结论如下:(1)通过室内物理模型实验发现,在相同试验条件下,同等体量的碎屑颗粒,颗粒的尺寸越大,其水平运动的距离越远,滑坡体的重心下降的越大,呈现出的流动性越强。并且,粒径大的岩石颗粒会使得滑坡面产生更大的振动的加速度,且引起振动的速度变化范围更大,而滑坡面的振幅却并不随颗粒粒径的变化而有所变化。(2)岩石滑坡碎屑流的远程阶段呈现出高速、远程的运动特点,其影响因素是滑坡体的滑动使得滑坡面产生了振动,从而导致了滑坡体与滑坡面之间的接触时间减短,则滑坡体在滑行过程中由于摩擦阻力的能量损耗就会降低,最终使得滑行的速度与水平运动的距离增大。而粒径越大岩石颗粒引起滑坡面振动的频率越高,则其与滑坡面接触的时间相比较粒径小的岩石颗粒更短,最终呈现出了颗粒粒径越大的滑坡体滑行的速度越快、滑行的距离越远的现象。(3)将岩石碎屑箱中的颗粒进行竖向分层之后发现,岩石碎屑颗粒在滑行之后会出现一个非常有趣堆积现象:处在上层的岩石颗粒,不论其运动的最远距离还是其最终分布的范围都比位于下层的岩石颗粒更大,并对这种现象的发生机理进行了分析。对于含有不同级配的岩石碎屑滑坡体,其水平运行的距离、堆积物的堆积长度与堆积宽度只与其中大粒径岩石颗粒含量有关。(4)利用PFC3D离散元分析软件对颗粒滑坡体进行模拟滑行之后,得出分层颗粒滑坡的速度与滑动距离的变化规律,其结论与室内物理模型实验的结果相符合。(5)对国内外29个高速远程滑坡碎屑流的记录数据进行标准化处理及分析之后得出:滑坡体高程与滑坡水平运行距离之间的关系呈线性的,而滑坡体体积与滑坡体运行距离之间的关系为非线性关系;并对影响滑坡水平运动距离的两个自变量因素进行分析比较之后认为,影响滑坡体水平运行距离的主要因素是滑坡体高程,次要影响因素是滑坡体体积,两个自变量回归分析的复测定系数分别为R2=0.816、R2=0.2933,即滑坡体高程更能影响其水平滑动距离。并由一元线性回归法得出滑坡体高程与水平运行距离之间方程式,由一元非线性回归法得出滑坡体体积与运行距离之间方程式。通过分析先确定出滑坡体水平运动距离与其高程、体积的方程形式,再由多元非线性回归法得出最终的标准回归方程式。
[Abstract]:Due to the high-speed long-distance landslide rock debris flow has strong liquidity, sliding speed, wide spread and many characteristics of sudden landslides forecast at the start and the movement path, the landslide occurred in people's life and property is under a great threat. Research results at home and abroad on the high-speed long-distance landslide rock the debris flow, but because it occurred before the early recognition ability is poor, which can not be timely, safe evacuation of personnel, resulting in casualties caused by such a catastrophic event continues. Therefore, is of great practical significance for the study of factor accumulation law of this high-speed remote landslide debris flow as well as the influence of the high speed and long distance the paper carries on indoor small scale physical model experiment of high-speed remote landslide rock debris flow, trying to find out the influence factors of rock and its high speed and long distance After the accumulation of debris flow. Then the regularities of distribution of rock landslide debris particles were simulated using the PFC3D discrete element analysis software, analysis of landslide speed, change of the distance, and compared with the experimental results of indoor physical model. Through the theoretical research of high-speed remote landslide debris flow, calculating equation level the landslide motion is derived distance, horizontal movement distance of high-speed remote landslide debris flow occurred after the prediction to provide a theoretical basis. The main conclusions are as follows: (1) through the indoor physical model experiments show that under the same experimental conditions, the same amount of debris particles, particle size is greater. The horizontal movement distance farther, the focus of landslide decline greater liquidity has a stronger. And rock particles of larger diameter makes the landslide surface produce greater vibration The dynamic acceleration and speed change range caused by vibration amplitude changes larger, but not slippery slope with the particle size change. (2) remote stage rock landslide debris flow presents the high speed, movement characteristics of distance, the influence factors of the landslide sliding is the landslide surface vibration, resulting in a short contact time between landslide and landslide, the landslide is in the sliding process due to the energy loss will reduce the friction resistance, eventually making speed and horizontal movement of sliding distance increased. And the particle size of the big stone particles caused a landslide surface vibration frequency is high, the shorter the rock particles with the landslide surface contact time compared to the small size, finally showing the landslide sliding particle size increasing faster, sliding distance farther. (3) the rock debris particles are in the box Find the vertical stratification, rock debris particles will appear a very interesting phenomenon in the accumulation of rock particles in the upper slide after, regardless of the distance of the movement or the final distribution range is larger than the rock particles in the lower layer, and the mechanism of this phenomenon is analyzed. The rock debris landslide with different gradation, the level of running distance, accumulation of accumulation of the length and width of the packing only with large diameter rock particles content. (4) after the body of particles is simulated by PFC3D landslide sliding discrete element analysis software, obtains the variation of speed and sliding distance of layered particle landslide, and the conclusions the indoor physical model test results are consistent. (5) obtained after recording data of 29 domestic and foreign high-speed remote landslide debris flow for processing and analysis of the landslide of high standard: The relationship between the process and the level of landslide running distance is linear, and the relationship between landslide volume and landslide running distance is nonlinear; and the two variables influencing factors of landslide horizontal movement distance are considered analysis, main factors affecting the level of landslide running distance is landslide elevation, secondary effects factors of landslide volume, complex determination of two variable regression coefficients were R2=0.816 and R2=0.2933, which could affect the landslide elevation level and sliding distance. A linear regression equation between the method of landslide body height and horizontal distance running, by a nonlinear regression equation between landslide volume and running distance. Through the analysis to determine the horizontal movement distance and elevation of the landslide, the volume equations by nonlinear regression method to obtain the final Standard regression equation.

【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45;P642.22

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