Department of Civil, Environmental and Infrastructure Engineering, George Mason University, Fairfax, VA 22030, USA.
Waste Manag. 2023 Feb 15;157:348-356. doi: 10.1016/j.wasman.2022.12.028. Epub 2023 Jan 7.
Hydraulic conductivity of the overlap region of two needle-punched sodium bentonite (Na-B) geosynthetic clay liners (GCLs) permeated with CaCl solutions under confining stresses of 20, 100, 250, and 500 kPa were evaluated. One of the GCLs consisted of a uniform layer of Na-B encapsulated between a nonwoven (NW) and a woven (W) geotextile, and the other one consisted of NW geotextiles on both sides. Supplemental bentonite was placed within the overlap region. Experiments were conducted with 10, 20, and 50 mM CaCl solutions representing dilute and aggressive leachates. The results indicate that in most of the scenarios there is a possibility that the flow is not completely vertical (meaning flow passes through the overlap region horizontally). As the confining stress increased, the horizontal flow through the overlap region for GCLs reduced effectively when permeated with deionized water and 10 mM CaCl solution, whereas the reduction of horizontal flow was limited to 20 mM and 50 mM CaCl solutions.
评估了在 20、100、250 和 500 kPa 围压下，浸透 CaCl 溶液的两层针刺钠基膨润土（Na-B）土工合成黏土衬垫（GCL）重叠区域的水力传导系数。一个 GCL 由一层均匀的 Na-B 夹在无纺（NW）和机织（W）土工织物之间组成，另一个 GCL 由两侧的 NW 土工织物组成。在重叠区域内添加了补充膨润土。实验采用 10、20 和 50 mM CaCl 溶液进行，代表稀溶液和腐蚀性浸出液。结果表明，在大多数情况下，流动可能不完全是垂直的（意味着流动通过重叠区域水平流动）。随着围压的增加，当用去离子水和 10 mM CaCl 溶液渗透时，GCL 中通过重叠区域的水平流动有效减少，而 20 mM 和 50 mM CaCl 溶液中水平流动的减少则受到限制。
