Effects of leachate infiltration and desiccation cracks on hydraulic conductivity of compacted clay  

作　　者：Jun He Yu Wang Yong Li Xiao-chen Ruan 

机构地区：[1]College of Civil and Architectural Engineering, Hubei University of Technology

出　　处：《Water Science and Engineering》2015年第2期151-157,共7页水科学与水工程（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51008120);the Youth Chenguang Project of Science and Technology of Wuhan City(Grant No.201271031418);the Outstanding Young Talent Program of Hubei Province(Grant No.2010 CDA091)

摘　　要：Both cracks in clay liner and the complex composition of landfill leachate might have effects on the hydraulic conductivity of a compacted clay liner. In this study, the hydraulic conductivities of natural clay and bentonite-modified clay with and without desiccation cracks were measured, respectively, using three types of liquids as permeating liquid： 2 500 mg/L acetic acid solution, 0.5 mol/L CaCl2 solution, and tap water. When tap water was adopted as the permeating liquid, desiccation cracks resulted in increases in the average value of hydraulic conductivity： a 25-fold increase for the natural clay and a 5.7-fold increase for the bentonite-modified clay. It was also found out that the strong selfhealing capability of bentonite helped to reduce the adverse impact of cracks on hydraulic performance. In contrast to tap water, simulated leachates（acetic acid and CaCl2 solutions） show no adverse effect on the hydraulic conductivities of natural and bentonite-modified clays. It is concluded that desiccation cracks and bentonite have more significant effects on hydraulic performance than simulated leachates.Both cracks in clay liner and the complex composition of landfill leachate might have effects on the hydraulic conductivity of a compacted clay liner. In this study, the hydraulic conductivities of natural clay and bentonite-modified clay with and without desiccation cracks were measured, respectively, using three types of liquids as permeating liquid： 2 500 mg/L acetic acid solution, 0.5 mol/L CaCl2 solution, and tap water. When tap water was adopted as the permeating liquid, desiccation cracks resulted in increases in the average value of hydraulic conductivity： a 25-fold increase for the natural clay and a 5.7-fold increase for the bentonite-modified clay. It was also found out that the strong selfhealing capability of bentonite helped to reduce the adverse impact of cracks on hydraulic performance. In contrast to tap water, simulated leachates（acetic acid and CaCl2 solutions） show no adverse effect on the hydraulic conductivities of natural and bentonite-modified clays. It is concluded that desiccation cracks and bentonite have more significant effects on hydraulic performance than simulated leachates.

关 键 词：Natural clay Bentonite-modified clay Hydraulic conductivity Solution Desiccation crack 

分 类 号：TU43[建筑科学—岩土工程] TV139.1[建筑科学—土工工程]