滑坡-碎屑流运动堆积特征与能量耗散规律

Motion and accumulation characteristics and energy dissipation laws of landslide-debris flow

为深入探究滑坡-碎屑流运动堆积特征与能量耗散规律,通过简化地形特征,考虑体积效应和启滑高度关键因素,建立室内滑坡碎屑流试验模型,监控并获取模型运动与堆积过程特征参数,揭示滑坡碎屑流运动学特征。此外,应用TS方法模拟滑坡碎屑流缩尺模型的运动全过程,反演获得碎屑流模型关键动力学参数,结合试验和数值方法定量研究碎屑流的运动过程(距离、厚度、速度等)、堆积特征以及能量转化规律。结果表明:滑坡体积与启滑高度对碎屑流最大运动距离的影响程度较为相近,启滑高度对堆积体宽度几乎没有影响;碎屑流平均速度先增大至峰值后逐渐减小,速度峰值受到启滑高度影响明显,碎屑流前缘速度显著大于中部及后缘速度;碎屑流重力势能转化为动能的效率在10%~25%,且转化效率随着启滑高度的增加而增大,而体积对转化效率影响较小。综合研究了滑坡碎屑流运动堆积特征和能量耗散规律,成果对滑坡碎屑流动力学机制研究提供支撑,对防灾减灾具有一定的价值。

In order to further study the motion and accumulation characteristics and energy dissipation landslide debris flow,we established an experimental model of landslide debris flow by simplifying terrain features and considering key factors such as volume effect and start slip height.The characteristic parameters and accumulation process are monitored and obtained to reveal the kinematic characteristics of landslide debris flow.In addition,the TS method is used to simulate the movement process of landslide debris flow,and the key dynamic parameters are obtained by inversion.Combined with experimental and numerical methods,we quantitatively studied the motion process(distance,thickness,velocity,etc.),accumulation characteristics and energy conversion law of debris flow.The results show that the landslide volume and slip height have similar effects on the maximum movement distance of debris flow,while slip height has minimal effect on the width of accumulation body.The average velocity with time is in the form of a parabolic downward opening,and the peak velocity is obviously affected by height,and the velocity of the leading edge is greater than that of the middle and trailing edge.The conversion efficiency of the gravitational potential energy into kinetic energy is between 10%and 25%,and the conversion efficiency increases with the height of start slip,while the volume has little effect on the conversion efficiency.This paper comprehensively investigates the accumulation characteristics and energy dissipation law of landslide debris flow,and the results provide support for the study of the mechanism of landslide debris flow mechanics,which is of certain value for disaster prevention and mitigation.