岩土力学2024，Vol.45Issue(1)：267-283,17.DOI:10.16285/j.rsm.2023.0053
基于计算流体力学-离散元耦合的相对密实度对断级配土体渗蚀效应的影响研究
Influence of soil relative density on suffusion of gap-graded soil based on coupled computational fluid dynamics-discrete element method
摘要
Abstract
The geometric characteristics of soil(gap ratio,fines content,relative density,etc.)not only affect the internal stability of soil but also have an important influence on suffusion development.Based on the coupled method of discrete element method(DEM)and computational fluid dynamics(CFD),a three-dimensional computation model of suffusion for internally unstable soil is established,the coupled effects of fines contents and relative densities on the suffusion are investigated,and the mesoscopic variables including soil constriction size distribution(CSD),coordination number and internal force transfer mechanism are analyzed to reveal the microscopic mechanism of the coupled influence from fines content and relative density.The results show that the increase in relative density decreases the erosion mass ratio,which is also highly related to fines content;the higher the fines content,the more obvious the effect of relative density.The specimen after erosion can be divided into"upstream erosion zone","central stable zone"and"downstream erosion zone".The increment of soil permeability during suffusion decreases with increasing relative density,while it increases with increasing fines contents.The influence of relative density on the suffusion process can be attributed to three aspects:differences in flow rates under the same hydraulic gradient,variations in the distribution of internal pore sizes,and variations in the contribution of fine particles to stress transmission within the soil.The results deepen the understanding of the influence of soil geometric characteristics on suffusion processes and provide a reference for the establishment of macroscopic erosion constitutive relationship.关键词
渗蚀/CFD-DEM/相对密实度/细粒含量/传力机制Key words
suffusion/CFD-DEM/relative density/fines content/stress transmission mechanism分类
建筑与水利引用本文复制引用
张沛云,木林隆,黄茂松..基于计算流体力学-离散元耦合的相对密实度对断级配土体渗蚀效应的影响研究[J].岩土力学,2024,45(1):267-283,17.基金项目
国家重点研发计划项目(No.2021YFB2600700) （No.2021YFB2600700）
上海市自然科学基金(No.22ZR1464600).This work was supported by the National Key R&D Program of China(2021YFB2600700)and the Natural Science Foundation of Shanghai(22ZR1464600). （No.22ZR1464600）
