深厚覆盖层侵蚀型管涌细观机理研究  

Study on micro mechanism of piping erosion in deep overburden

作　　者：倪小东[1] 寇恒绮 史志鹏 王媛[1] NI Xiaodong;KOU Hengqi;SHI Zhipeng;WANG Yuan(School of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098

出　　处：《华中科技大学学报（自然科学版）》2023年第10期134-141,共8页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家重点研发计划资助项目(2019YFC1510800);国家自然科学基金联合基金重点资助项目(U2240210);江苏省水利科技资助项目(2021075)。

摘　　要：为研究深厚覆盖层侵蚀型管涌的细观机理,基于DEM-CFD(离散元-计算流体力学)方法,构建了颗粒-孔隙尺度耦合分析模型,开展了不同水力梯度下深厚覆盖层侵蚀型管涌的数值模拟,从骨架颗粒接触力链网络的角度揭示了水力梯度对侵蚀型管涌发展的影响,并根据数值模拟的结果对细颗粒流失概率理论进行改进.结果表明:随着水力梯度的增大,细颗粒流失量减小,细颗粒流失达到稳定的时间提前,运移距离大于100 mm的细颗粒数量增多,运移距离小于100 mm的细颗粒数量减少;水力梯度越大,接触力数目越多,强接触占接触总数比例减小,接触力向y轴方向收拢;改进理论对细颗粒流失概率的预测与既有研究中数值模拟的结果较为接近.To study the micro mechanism of piping erosion in deep overburden,based on DEM-CFD(discrete element methodcomputational fluid dynamics)method,a particle-pore scale coupling analysis model was constructed,and the numerical simulation of deep overburden piping erosion under different hydraulic gradients was carried out.The influence of hydraulic gradient on the development of piping erosion was revealed from the perspective of skeleton particle's contact force chain network,and the fine particle loss probability theory was improved according to the results of numerical simulation.Results show that with the increase of hydraulic gradient,the loss of fine particles decreases,the time of fine particle loss reaching stability is advanced,the number of fine particles with transport distance greater than 100 mm increases,and the number of fine particles with transport distance less than 100 mm decreases.The larger the hydraulic gradient is,the more the number of contact force is,and the smaller the proportion of strong contact to the total number of contacts is,the closer the contact force to the y axis is.The prediction of fine particle loss probability by the improved theory is close to the result of numerical simulation in the existing research.

关 键 词：侵蚀型管涌 数值模拟 力链网络 喉管 细颗粒运移 

分 类 号：TV223.4[水利工程—水工结构工程]