咸水体修复过程中含水层物理堵塞试验研究

针对山东半岛大沽河下游咸水体修复过程中含水介质物理堵塞的问题,采用室内模拟试验,系统研究了悬浮物质量浓度和粒径对咸水体含水介质物理堵塞的影响,并通过测定人工回灌过程中渗透系数的时空变化,定量分析和评价含水介质物理堵塞的机理和程度。结果表明:悬浮物质量浓度和粒径是影响含水介质渗透性的关键因素; 在悬浮物质量浓度分别为50、100、200 mg·L^-1的条件下,含水介质的等效渗透系数分别为其初始值的38%、20%和10%; 随着注入悬浮物质量浓度、注入时间的增加和入渗深度的减小,相对渗透系数不断减小; 悬浮物的粒径越小,迁移距离越大,造成渗透系数下降区的厚度越大; 随着悬浮物粒径的不断增大,粒径大的颗粒容易被截留在表层,造成表层渗透系数下降幅度增大,其余各层渗透系数下降幅度随深度增加而减小。

Test Study on Physical Clogging of Aquifer During the Restoration of Saline Water Mass

In order to solve the physical clogging problem of aquifer in Dagu River downstream during the restoration of saline water mass, effect of mass concentration and particle size of suspended matter on the physical clogging of aquifer in saline water mass was systematically studied with field simulated test; the temporal and spatial variations of permeability coefficient during the artificial recharge were measured to evaluate the degree and mechanism of physical clogging quantificationally. The results showed that mass concentration and particle size of suspended matter were the key factors for penetrability of aquifer; when the mass concentrations of suspended matter were 50, 100, 200 mg·L^-1, the equivalent permeability coefficients of aquifer were 10%, 20% and 38% of the initial value, respectively; the relative permeability coefficient decreased gradually with the increase of recharge time and mass concentration of suspended matter and the decrease of infiltration depth; the smaller the particle size of suspended matter was, the longer the migration distance was, the larger the thickness of area with permeability coefficient descending was; with the increase of particle size of suspended matter, the suspended matter was easily intercepted by the surface layer of sand column, so that the decrease amplitude of permeability coefficient of surface layer increased, and the decrease amplitude of other layers decreased with the increase of depth.