Numerical investigation of the effect of geosynthetic clay liner chemical incompatibility on flow and contaminant transport through a defective composite liner  

作　　者：Shiyuan YAO Yuchao LI Shan TONG Guannian CHEN Yunmin CHEN 

机构地区：[1]MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Department of Civil Engineering,Zhejiang University,Hangzhou 310058 China [2]School of Civil&Environmental Engineering and Geography Science,Ningbo University,Ningbo 315211,China [3]Ningbo ZCONE High-tech Co.,Ltd.,Ningbo 315000,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2023年第7期557-568,共12页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：supported by the National Key Research and Development Program of China(Nos.2018YFC1802304 and 2019YFC1806002);the National Natural Science Foundation of China(Nos.42077241 and 51988101)。

摘　　要：A composite liner consisting of a geomembrane(GMB)and a geosynthetic clay liner(GCL)can be compromised by inorganic contaminants because of a defective GMB.When the composite liner with defective GMB is exposed to aggressive leachate conditions,the neglect of the chemical incompatibility of the GCL can potentially result in an underestimation of the leakage rate and flux through the composite liner.This paper proposed a numerical investigation on the effect of chemical incompatibility of GCL on the barrier performance of the composite liner with hole defect.Four cases with leachate solutions having varied cation valencies and ionic strengths were analyzed,in which the hydraulic conductivity of GCL was concentrationdependent.Both the effect of the chemical incompatibility of GCL and the mechanisms were analyzed.The incompatibility of GCL resulted in significant increases in leakage rate and flux through the composite liner by factors of up to 4.9 and 5.0,respectively.The incompatibility-affected area in GCL is located within 0.1 m from the center of the hole in the GMB.The coupled increase in the hydraulic conductivity of GCL and pore water concentration impacts the flux and leakage in a short period of time.With GCL chemical incompatibility considered,advection may dominate the contaminant transport through GCL.

关 键 词：Geosvnthetic clay liner(GCL) Chemical incompatibility LEAKAGE Contaminant transport Hvdraulic conductivity 

分 类 号：TU43[建筑科学—岩土工程] X50[建筑科学—土工工程]