岩石碎屑流运移堆积过程数值模拟

NUMERICAL SIMULATION OF FLOW AND DEPOSITOIN PROCESS OF ROCK AVALANCHE

岩石高速远程崩滑是一种特殊的、危害性很大的地质灾害,崩滑后期形成的高速岩石碎屑流具有很高的运移能力,破坏力极强。以岩石碎屑流为研究对象,重点模拟岩石碎屑流形成后,碎屑流的运移堆积过程和最大运移堆积距离。利用二维颗粒离散元数值模拟方法,建立碎屑流二维运动堆积模型,分析了岩石碎屑流初始高度、体积、加速斜面坡度、堆积底面摩擦系数以及堆积底面地表起伏程度对于岩石碎屑流最大运移堆积距离的影响。实验结果显示:岩石碎屑流运移堆积过程体现出了碎屑流物质的离散性和流动性;碎屑流最大堆积距离随高度、体积、斜面坡度增大而增大;随堆积底面摩擦系数、堆积底面地表起伏程度增大而减小。

Large rock slides e and then subsequent broken rock mass avalanches are one of the most destructive geological hazards in the world.Especially,the rock avalanches have intensive run-out ability and destructive power.This paper mainly studies the flow and deposition mechanism of rock landslide induced avalanche.Using a two-dimensional particle flow method,this paper numerically examines the influence of the original height,volume,slope angle and depositing substrate＇s frictional coefficient and waviness to avalanches.Numerical test results reveal that：（a）the flow and deposition process of a rock avalanche present a discrete and fluid-like nature;（b）increasing in the original height,the volume of rock avalanche and the slope angle would increase the maximum run-out length;and（c）increasing in the frictional coefficient and waviness of the deposition substrate would decrease the maximum run-out length.