用于咸寒地区渠道衬垫的GCL特性试验

Experimental studies on characteristics of GCL used for channel liner in cold regions

为了研究GCL膨润土防水毯用于咸寒地区渠道衬垫系统的有效性,对膨润土防水毯进行水化试验、干湿循环试验、冻融循环试验、自愈能力试验,研究GCL的膨胀和渗透特性,分析影响材料渗透系数的因素。结果表明:水化液对材料的渗透性影响较大,离子浓度越高,渗透系数越大,未经水化的材料不能直接用于施工中;材料经历干湿循环后,渗透系数变化不大,并具有良好的自愈性;随着冻融循环次数的增加,渗透系数逐渐减小,GCL在严寒条件下能保持良好的防渗性;膨润土的压缩率与渗透系数呈正相关,变形随着冻融次数的增加而减小,抗变形能力增加,GCL可用于北疆严寒区渠道防渗。

In order to investigate the feasibility of using geosynthetic clay liner （GCL） for channel liner systems in cold and salty soil regions, several tests were conducted, including a hydration test, drying-wetting cycle test, freeze-thaw cycle test, and self-healing test. The swelling and permeability characteristics of GCL were studied, and the factors influencing the permeability coefficients of GCL were analyzed. The results show that the hydration solution greatly affects the permeability of the material： the higher the ion concentration is, the greater the permeability coefficient is; and the material cannot be used in construction without hydration. After drying-wetting cycles, the permeability coefficient of the material changes a little, owing to its high self-healing capability. The permeability coefficient gradually decreases with the increase of the number of freeze-thaw cycles, indicating that the material can maintain high impermeability under cold conditions. The bentonites＇ compressibility and permeability coefficient are positively correlated; the degree of deformation decreases with the increasing number of freeze-thaw cycles, meaning that the ability of resistance to deformation of the material increases. GCL can be used in channel liner in cold regions, in the northern China.