摘要
基于坡面泥石流室内模型试验结果,利用三维颗粒流数值模拟软件PFC3D对不同条件下坡面泥石流的启动过程进行了模拟研究,并探讨了坡面泥石流的启动机理.结果表明:降雨开始时,由于土体初始含水率低,雨水首先会向下入渗进入土体,且在坡体表层率先形成饱和区,饱和区内会产生坡面径流,导致坡表率先被破坏,最终产生坡面泥石流;坡角越大,坡体的稳定性越差,在相同的降雨条件下更容易发生坡面泥石流,且土体的滑动距离越远、滑动体积越大;坡表饱和区越厚,发生的坡面泥石流规模越大;土体的抗剪强度越小(即土体的摩擦系数越小),发生的坡面泥石流规模越大.本研究可为泥石流灾害的预测和预防提供依据.
Based on the laboratory model test results of the slope debris flow,the particle flow code numerical simulation software PFC3D is used to simulate the startup process of the slope debris flow under different conditions,and the startup mechanism of the slope debris flow is discussed. The results show that at the beginning of rainfall,due to the low initial moisture content of the soil mass,the rainwater first infiltrates into the soil mass,resulting in the formation of the saturated area on the surface of the slope body firstly. Then the slope runoff is generated in the saturated area,which leads to the destruction of the slope surface first,and finally the debris flow on slope occurs. Under the same hydraulic condition,the larger the slope angle is,the worse the stability of the slope body is,and the slope debris flow is more likely to occur. The thicker the saturation area on the slope surface is,the larger the scale of the slope debris flow is. The smaller the shear strength of soil mass(that is,the friction coefficient of soil mass)is,the larger the scale of the slope debris flow is. This study can provide a basis for the prediction and prevention of debris flow disaster.
作者
王乐荣
石崇
翟淑花
张一平
马金城
WANG Lerong;SHI Chong;ZHAI Shuhua;ZHANG Yiping;MA Jincheng(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China;Research Institute of Geotechnical Engineering,Hohai University,Nanjing 210024,China;Beijing Institute of Geology,Beijing 100120,China)
出处
《河南科学》
2022年第3期419-426,共8页
Henan Science
基金
国家自然科学基金(51679071)。
关键词
坡面泥石流
启动机理
颗粒流
细观数值模拟
坡表饱和区厚度
slope debris flow
startup mechanism
particle flow code
mesoscopic numerical simulation
thickness of saturation zone on slope surface
