本项目拟以考虑化-渗耦合作用的、红黏土-膨润土工程屏障对重金属污染物的迁移阻滞特性，以及工程屏障系统的自修复机制为研究目标，通过开展吸附/解吸附、渗透和迁移、土体材料化学相容性和土体自愈性等试验，揭示化-渗耦合作用下、工程屏障对重金属污染物的阻滞特性及物化自修复机理；结合理论分析和数值计算，建立基于化-渗耦合作用的土体渗透及污染物迁移转化模型；分析工程屏障材料的长期化学相容性，探讨红黏土-膨润土混合土体的自愈性特征；基于“阻滞-自修复”的理念，提出工程屏障系统长期安全性能的评价方法。预期研究成果对于促进地质工程、环境科学、化学和材料科学等学科交叉，指导我国重金属污染场地中工程屏障系统的设计、施工和维护，实现土壤和地下水重金属污染的防治等均具有重要的学术意义和工程实践价值。

The purpose of this project is to investigate the retention property and self-healing mechanism of an engineered barrier, which is constructed by laterite-bentonite mixture, for blocking-up migration of heavy metal contaminants with consideration of chemo-hydraulic coupling effects. For these purposes, the adsorption/desorption tests, infiltration and migration tests, soil chemical compatibility tests, soil self-healing tests will be conducted. Then, the heavy metal contaminants retention characteristics and physical-chemical self-healing mechanisms of laterite-bentonite engineered barrier with consideration of chemo-hydraulic coupling effects will be explored. Based on theoretical analyses and numerical calculations, groundwater flow and heavy metal contaminants migration/transformation models will be established. Meanwhile, the long-term chemical compatibility of engineered barrier materials will be analyzed and the self-healing properties of laterite-bentonite mixture will be discussed. According to the concept of "Retention and self-healing", a method will be proposed for long-term safety evaluation of engineered barrier system. The research results expected in this project will effectively promote the interdisciplinary developments among Geological Engineering, Environmental Science, Chemistry and Materials Science, etc. This project is proposed to provide a theoretical basis for the design, construction and maintenance of the engineered barrier system. Moreover, this research has great academic and practical significances for control and remediate heavy metal contaminated soil or groundwater in China.