Geosynthetic clay liner (GCL) is commonly used in cover system of engineered landfill to limit migration of gases and infiltration of water. In engineered landfill, gas transfer occurs by advection and diffusion, which may take place at different time frames or simultaneously depending on placement conditions. Hence, efficacy of GCL as a gas barrier under advection and diffusion needs to be assessed at various geoenvironmental settings. In the present study, the gas flow response of GCL under advection and diffusion were evaluated at various apparent degrees of saturation, distortion levels, hydrating fluids, and wet-dry cycles using custom-designed test apparatus. Gas permeability and gas diffusion coefficient of GCL were found to decrease by four and three orders of magnitude respectively with an increase in apparent degree of saturation from 7% to 80%. Gas permeability and gas diffusion coefficient were increased with an increase in distortion levels. With an increase in wet-dry cycles 1 to 5, gas permeability and gas diffusion of GCL were increased marginally when hydrated with distilled water while increased by one order of magnitude for hydrated with 0.0125 M CaCl₂ solution. The obtained results were compared with published results and found to be in good agreement.

中文翻译：

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GCL 在变形、干湿循环和水化流体下的气流特性

土工合成粘土衬里 (GCL) 通常用于工程垃圾填埋场的覆盖系统，以限制气体迁移和水渗透。在工程垃圾填埋场中，气体转移通过平流和扩散发生，这可能发生在不同的时间范围内或同时发生，具体取决于放置条件。因此，需要在各种地质环境设置下评估 GCL 在平流和扩散下作为气体屏障的功效。在本研究中，使用定制设计的测试设备在各种表观饱和度、变形水平、水合流体和干湿循环下评估了 GCL 在平流和扩散下的气流响应。随着表观饱和度从 7% 增加到 80%，GCL 的气体渗透率和气体扩散系数分别降低了四个和三个数量级。气体渗透率和气体扩散系数随着变形水平的增加而增加。随着干湿循环 1 到 5 的增加，GCL 的透气性和气体扩散在用蒸馏水水合时略有增加，而在用 0.0125 M CaCl 水合时增加一个数量级₂解决方案。将获得的结果与已发表的结果进行比较，发现它们非常吻合。