渗流条件下夹层砂土中细颗粒迁移沉积特性试验研究OA北大核心CSTPCD
Experimental study on migration and deposition characteristics of fine particles in sandwich sand under seepage condition
夹层砂土中细颗粒迁移-沉积问题广泛存在于地下水回灌、堆积体入渗、反滤层设计及注浆等工程中.采用室内一维砂柱试验系统,选取3种典型粒径砂土,开展了2种夹层位置及厚度下砂土中悬浮颗粒迁移-沉积特性试验研究.结果表明:在夹层砂柱中,粒径对细颗粒迁移-沉积过程影响显著.粒径比大于1时,悬浮颗粒穿透曲线峰值更高,在夹层处产生细颗粒沉积量突增现象;夹层位置越靠近注水端,厚度越小,其峰值和沉积突增量越大.粒径比小于1时,悬浮颗粒穿透曲线峰值较低,夹层处无颗粒富集;夹层越靠近出水端,厚度越大,穿透曲线的峰值也越高.试验过程中,悬浮颗粒的迁移沉积会引起渗透系数变化.渗透系数变化过程与穿透曲线变化相对应,过程分为沉积、剥离迁移和动态平衡三种.细颗粒在砂土中以吸附方式沉积,并在吸附处堆积.
The problem of migration-deposition of fine particles in sandy soils with interbedded layers is widespread in groundwater recharge,infiltration of piles,design of reverse filtration layer and grouting.Using an indoor one-dimensional sand column test system,three kinds of sandy soils with typical grain sizes were selected,and the migration-deposition characteristics of suspended particles in sandy soils were investigated in two kinds of interlayer locations and thicknesses.The results show that the particle size has a significant effect on the migration-deposition process of fine particles in sand columns with interlayers.When the particle size ratio is larger than 1,the peak value of the suspended particles penetration curve is higher,and the amount of fine particles deposited in the interlayer increases abruptly;the closer the interlayer position is to the water injection end,the smaller the thickness is,and the larger the peak value and the sudden increase in deposition are.When the particle size ratio is less than 1,the peak value of the suspended particles penetration curve is lower,and there is no particle enrich-ment at the interlayer;the closer the interlayer is to the water outlet end,the greater the thickness,and the higher the peak value of the penetration curve.During the test,the migration and deposition of suspended particles will cause changes in the permeability coefficient.The process of permeability coefficient change corresponds to the change of penetration curve,and the process is divided into three kinds:deposition,stripping migration and dy-namic equilibrium.Fine particles are deposited in sandy soil by adsorption and accumulate at the adsorption.
崔先泽;周钰錩;范勇;杨广栋
水电工程施工与管理湖北省重点实验室三峡大学,湖北宜昌 443002||三峡大学水利与环境学院,湖北宜昌 443002||流域水资源与生态环境科学湖北省重点实验室长江水利委员会长江科学院,湖北武汉 430010水电工程施工与管理湖北省重点实验室三峡大学,湖北宜昌 443002||三峡大学水利与环境学院,湖北宜昌 443002
土木建筑
夹层粒径比迁移沉积渗透系数
interlayerparticle size ratiomigrationdepositionpermeability coefficient
《水利学报》 2024 (008)
977-989 / 13
长江科学院开放研究基金项目(CKWV20221036/KY);湖北省自然科学基金项目(2022CFB248);国家自然科学基金项目(41702254)
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