抗盐型GCL膨胀和渗透性试验研究  

Swelling and Permeability Performance of Salt-resistant Geosynthetic Clay Liner

作　　者：边策[1] 田正宏[1] 李雪宁 刘剑波[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]中国电建集团昆明勘测设计研究院有限公司,云南昆明650000

出　　处：《水电能源科学》2016年第4期82-84,39,共4页Water Resources and Power

基　　金：国家自然科学基金项目(51279054);江苏省普通高校研究生科研创新计划项目(1044/B14053)

摘　　要：针对高含盐环境中普通膨润土防水毯(GCL)抗渗性能严重衰减问题,选取羧甲基纤维素钠(CMC-Na)作为添加剂与膨润土混合,通过试验测定混合物的膨胀指数,再据此制成抗盐型GCL(改性膨润土),并测定其在不同浓度、阳离子盐溶液、长期海水浸泡条件下的渗透系数变化情况。结果表明,常规膨润土在高含盐溶液及海水干湿循环作用下膨胀指数较低,但添加CMC-Na后膨胀指数明显提高;添加CMC-Na制成的抗盐型GCL的渗透系数随着水化液浓度及阳离子价位数升高而增大,但明显低于普通GCL;海水长期浸泡环境下抗盐型GCL渗透系数变化较小,低于普通GCL,且与其膨润土膨胀指数有较好相关性。据此可利用掺加CMC-Na以有效改善高含盐环境下的防渗效果。Aiming at preventing severe degradation in impervious performance of ordinary geosynthetic clay liner（GCL）in high salt environment,a new salt-resistant GCL within which sodium carboxymethylcellulose（CMC-Na）as additives was mixed with bentonite is developed,and its permeability coefficient and the mixture swelling index under conditions of long-time seawater immersion and saline solution having different concentrations and cations are tested.Test results show that：The swelling index of ordinary bentonite is relative low in saline solution and seawater under wet-dry cycle but increases significantly after mixed with CMC-Na.The permeability coefficient of salt-resistant GCL increases with increasing solution concentration and cationic valence but it is always much lower than that of ordinary GCL without adding CMC-Na.The permeability coefficient of salt-resistant GCL is also lower than that of ordinary GCL and does not change with time obviously when immersed into seawater for a long time.Furthermore,it can be noted that the permeability coefficient of salt-resistant GCL has a good correlation with the corresponding swelling index of mixture.Therefore,it can be concluded that the new salt-resistant GCL has a satisfied impervious performance in high salt environment.

关 键 词：抗盐型GCL 羧甲基纤维素钠 渗透系数 膨胀指数 

分 类 号：TV443.3[水利工程—水工结构工程]