滑坡-碎屑流冲切铲刮效应的颗粒离散元模拟

滑坡-碎屑流运动沿程冲切铲刮作用对滑坡运动性态(如速度、体积、物质组成等)具有重要影响,如何更好的进行模拟是滑坡动力过程分析的重要技术难题。在室内滑坡-碎屑流物理模型试验的基础上,采用三维颗粒流程序(PFC3D)对滑坡-碎屑流运动过程中对松散基底物质的冲切铲刮效应进行数值模拟,重点分析滑坡方量和滑落高度、基底厚度和强度以及地形坡度等因素的影响。结果表明:随着滑坡方量与滑落高度的增大,铲刮能量增加、铲刮作用时间延长,从而增强了铲刮效应;基底厚度的减小与地形坡度的增加均会引起基底物质稳定性降低,从而在同等条件下更易于被冲切铲刮;颗粒离散元方法是滑坡运动模拟分析的一种有效手段,模拟结果对于更好的理解滑坡运动冲切铲刮效应具有重要意义。

Particle discrete element simulation on punchingshear and scraping effect of landslide-debris flow

Entrainment effect among the mass movement process of debris avalanche has a great influence on the motion characteristics (such as velocity，volume and material composition) of landslides. How to make a better simulation is an important technical problem for the landslide dynamic process analysis. On the basis of an indoor physical model experiment of landslidedebris flow，the punchingshear and scraping effect during the landslide-debris flow movement process on the substrate substance therein is numerically simulated herein with 3 － D particle flow code (PFC3D)，in which the effects from the factors of landslide volume，sliding height，the thickness and strength of substrate as well as topographic slope are mainly analyzed. The result shows that the scraping energy is increased and the time of scraping effect is prolonged along with the increases of landslide volume and sliding height，thus the scraping effect is enhanced. Both the decrease of substrate thickness and the increase of sliding height can lead to the decrease of the stability of the substrate substance and make it more prone to be punchingsheared and scraped under the same condition. The particle discrete element method is an effective means for the simulative analysis of landslide movement，from which the simulation result has an important significance for better understanding the punchingshear and scraping effect during the landslide-debris flow movement process.