黏性碎屑流坡面运动过程数值模拟与检验

Numerical simulation and verification about viscous debris motion process on slope

由无黏粗颗粒与黏性泥浆组成的黏性碎屑流,其运动过程会产生不连续变形,基于连续介质假定的流体理论无法描述。根据散体材料理论,在考虑黏性泥浆影响情况下,以PFC3D为平台,编写黏性碎屑坡面运动数值模型试验程序,根据泥浆(成都黏土,密度1.413 g/cm3)室内拉伸试验和旋转剪切试验结果,设置数值模型参数,开展黏性碎屑流坡面运动数值模型试验,再现黏性碎屑坡面运动过程及运动过程中不连续变形现象,并通过同尺寸黏性碎屑坡面运动物理模型试验进行验证。结果表明:基于散体材料理论的PFC3D离散单元法能很好地再现黏性碎屑坡面运动过程及运动过程中不连续变形现象,为深入分析黏性泥浆介质影响下黏性碎屑坡面运动过程提供新的途径。

Since viscous debris flow is comprised of coarse particles and viscous mud, its movement process exhibits discontinuous deformation. Thus the fluid theory, which is based on continuous medium assumption, is difficultly applied to describe the process. Considering the influence of viscous media, a numerical model for viscous debris movement is firstly compiled according to the theory of granular materials and the platform of PFC3D software. Then the model parameters are obtained from the experimental results of indoor tensile tests and rotary shear tests on the viscous mud, which is called Chengdu clay and its density is 1.413 g/cm3.Moreover, numerical simulation of viscous debris movement is performed, which reproduces the movement process and the phenomenon of discontinuous deformation during the process. Meanwhile, the numerical simulations are verified by the experiment with the same size of the physical model. The results show that the PFC3D discrete element method, based on theory of granular materials, is applicable to simulate the movement process and present the phenomenon of discontinuous deformation during the movement process of viscous debris soil. This study provides a new way for further analyzing the viscous debris movement on slope under the impact of viscous media.