Evaluation of the Environmental Impact due to the Geotechnical Utilization of Waste Materials

为促进废弃物的岩土利用，最大限度地减少地面污染，开展了废弃物再利用的地质环境影响评价研究。本研究取得的主要成果如下：(1)在设计方法方面，系统地总结和发展了许多岩土工程应用中的废弃物利用技术和危险化学品地面污染控制技术。(2)通过多种淋溶试验方法，评价了垃圾岩土工程利用对环境的影响。重点讨论了模拟现场浸出行为的试验方案，包括废物的粒度和暴露在水中的条件。通过室内试验研究了pH和氧化还原对土壤重金属淋失量和土壤衰减能力的影响。(3)在室内淋溶试验的基础上，提出了废物资源化处置对地质环境影响的简化评价方法。使用所提出的方法评估了减少环境影响的各种措施(例如，滤层、废物稳定化或粘土衬垫)的有效性。(4)提出了评价垃圾填埋场衬层(土工膜、粘土衬层、复合衬层)性能的方法，重点研究了双层衬层系统的效果。在参数研究的基础上，提出了适合内陆和近海垃圾填埋场的衬砌结构。

Evaluation of the geo-environmental impact due to the reuse of waste materials was studied to promote the geotechnical utilization of them and minimize the ground contamination. The main results obtained by this study can be summarized as follows : (1) A lot of techniques to utilize the waste materials in geotechnical applications and control the ground contamination with hazardous chemicals were developed and summarized systematically, mainly in aspect of the design method. (2) Environmental impact due to the geotechnical utilization of waste materials was evaluated through several leaching test methods. The main concern is given to the testing protocols, including the particle size of waste and the conditions exposing to water, to simulate the in-situ leaching behavior. The pH and redox effects on the leaching amount of heavy metals and the attenuation capacity of soil were also assessed by laboratory tests. (3) Simplified methods for evaluating the geo-environmental impact due to the reuse and disposal of waste materials were proposed based on laboratory leaching tests. The effectiveness of various measures to reduce the environmental impact (e.g., filtration layers, the stabilization of wastes, or clay liners) was evaluated using the proposed methods. (4) The methods for evaluating the performance of landfill liners (geomembrane, clay liner, composite liner) were also proposed with the focus on the effectiveness of the double liner system. An appropriate liner structure of the inland and offshore landfill sites was proposed based on the parametric studies using the proposed methods.