渗蚀过程中孔结构参数对细颗粒流失的影响  

Effect of pore structure parameters on loss of fine grain during suffusion

作　　者：魏海江 许增光[1] 耿凯强 冯上鑫 WEI Haijiang;XU Zengguang;GENG Kaiqiang;FENG Shangxin(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi′an University of Technology,Xi′an,Shaanxi 710048,China;School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi′an,Shaanxi 710054,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048 [2]西安科技大学建筑与土木工程学院,陕西西安710054

出　　处：《排灌机械工程学报》2023年第4期417-424,432,共9页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51922088,52179143);陕西省科技创新团队建设项目(2022TD-01)。

摘　　要：利用核磁共振监测了渗蚀过程中孔隙分布的演变规律,并通过自编程序测量了流失细颗粒的粒度分布,最后,基于灰色系统理论讨论了孔结构参数对细颗粒流失的影响.结果表明,初始细颗粒百分数越小的试样渗蚀越严重.水力梯度恒定时,累计细粒流失百分比随时间呈指数增大,渗蚀过程可分为发展、缓蚀和平衡阶段.细粒对渗蚀的敏感性随粒径的减小而增强,而表面形态对细颗粒运移的影响程度随粒径的减小而减小.渗蚀过程中土-水相互作用的强度与细颗粒百分数和水力梯度分别呈正相关关系.总体而言,收缩尺寸分布的连通性和非均质性逐渐增强,复杂程度逐渐减弱,等效开口尺寸逐渐增大.孔结构参数对颗粒流失的影响程度从大到小依次为分形维数、不均匀系数、控制收缩尺寸、最可几孔径.The evolution of pore size distribution during suffusion was monitored by nuclear magnetic resonance,and the grain size distribution of lost fines was measured by a self-programmed particle size recognition program.Finally,the influence of pore structure parameters on the loss of fines was discussed using gray system theory.The results show that the lower the initial fines content,the more severe the suffusion.When the hydraulic gradient is constant,the cumulative fines loss percentage increases exponentially with time,and the suffusion process can be divided into development,slow erosion and equilibrium stage.The sensitivity of fines to suffusion increases with the decrease of grain size,while the influence degree of surface morphology on the migration of fines decreases with the decrease of grain size.The intensity of the soil-water interaction during the suffusion is positively correlated with the initial fines content and hydraulic gradient,respectively.In general,the connectivity and heterogeneity of constriction size distribution gradually increase,the complexity gradually decreases,and the equivalent opening size gradually increases during the suffusion.The influence of pore structure parameters on fines loss from large to small is as follows:fractal dimension,non-uniform coefficient,controlled constriction size,and most probable pore size.

关 键 词：渗蚀 细颗粒流失 孔径分布 核磁共振 灰色系统理论 

分 类 号：TV698.233[水利工程—水利水电工程]