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研究重金属Cu2+离子的侵入对土体渗透特性的影响。以人工配置的CuCl2溶液作为渗透液,采用三联式柔性壁渗透仪在室内开展两种工况下污染土渗透试验,分别考虑围压和渗透污染液浓度对土体渗透性的影响。试验结果表明,配制的CuCl2溶液浓度保持恒定时,渗透液无论采用纯净水还是CuCl2溶液,土体渗透系数均随着施加围压的增大而减小,但是相同围压作用下CuCl2溶液作为渗透液,测得土体的渗透系数小于纯净水作用的渗透系数,并且随着围压的增大,渗透系数的减小量呈现出逐渐缩小的趋势,直至围压超过500kPa后流体特性对土体渗透性的影响不大。施加围压相同而渗透液浓度不同的情况下,土体渗透系数随着CuCl2溶液浓度的增加先急剧减小随后则逐渐增大。微观结构分析结果表明,CuCl2溶液作为渗透液时土体渗透系数与纯净水渗透存在差异的主要原因是缘于重金属Cu2+改变了黏土的内部结构,影响了黏土的孔隙大小,从而造成了宏观渗透性的差异。
Study on the infiltration of heavy metals Cu2 + ions on the infiltration characteristics of soil. Using artificial confined CuCl2 solution as permeate, the three-way flexible wall permeameter was used to carry out indoor permeation test of contaminated soil under two different operating conditions. The influence of confining pressure and concentration of infiltrated pollutant on soil permeability was considered. The experimental results show that when the concentration of CuCl2 solution is kept constant, the permeability coefficient of soil decreases with the increase of confining pressure, no matter using pure water or CuCl2 solution. However, under the same confining pressure, Liquid, the measured permeability coefficient of soil is less than the effect of pure water permeability coefficient, and with the confining pressure increases, the decrease of permeability coefficient shows a trend of decreasing until the confining pressure exceeds 500kPa fluid characteristics of soil Permeability has little effect. Under the condition of the same confining pressure and different permeate concentrations, the permeability coefficient of soil decreases sharply with the increase of CuCl2 concentration and then increases gradually. The results of the microstructure analysis show that the main reason that the difference between the permeability coefficient of pure water and the permeation coefficient of pure water when the CuCl2 solution is used as permeate is that the internal structure of the clay changes due to the heavy metal Cu2 + and affects the pore size of the clay, resulting in macroscopic permeability The difference.