Clayey soils rich in smectite are commonly utilized for the construction of liner materials in engineered landfills owing to their low hydraulic conductivity. However, due to the high swelling potential of such clayey soils, their hydraulic conductivities are adversely influenced by desiccation cracking. In addition to cracks, the hydraulic conductivity of the clayey soils might also be affected by the complex composition of landfill leachate. The current study aims, therefore, to assess the effects of desiccation-induced cracks and leachate infiltration on the hydraulic conductivity of natural and 30% olivine-treated marine clay specimens. Clay specimens were prepared using three compactive energies and subjected to cycles of drying–wetting and hydraulic conductivity testing using tap water and field leachate as the permeants. Test results demonstrate significant improvements in the hydraulic conductivity of the olivine-treated clay samples after cycles of drying–wetting upon permeation with water and leachate. These improvements are attributed to the formation of magnesium–aluminate–hydrate and magnesium–silicate–hydrate gels as confirmed using microstructural analyses. The gels are responsible for minimizing the adverse impact of cracks on the hydraulic conductivity of the treated clay specimens. The findings indicate that olivine can be employed as a suitable additive in decreasing the hydraulic conductivity of soils prone to cracking.

中文翻译：

---

干燥引起的开裂和渗滤液渗透对天然和橄榄石处理的海洋黏土水力传导率的影响

富含绿土的粘土土壤由于其低水力传导性，通常用于工程垃圾填埋场的衬里材料的构造。然而，由于这种粘土的高膨胀潜力，其水力传导性受到干燥裂纹的不利影响。除了裂缝外，粘土质土壤的水力传导性还可能受到垃圾渗滤液组成的复杂性的影响。因此，当前的研究旨在评估干燥引起的裂缝和渗滤液渗透对天然和30％橄榄石处理过的海洋黏土样品的水力传导率的影响。利用三种压实能量制备了粘土试样，并使用自来水和田间渗滤液作为渗透剂进行了干湿循环和水力传导率测试。测试结果表明，经过水-渗滤液渗透和干燥后，经过橄榄石处理的粘土样品的水力传导率有了显着改善。这些改进归因于微结构分析证实的铝酸铝水合物凝胶和硅酸镁水合物凝胶的形成。凝胶负责使裂纹对处理过的粘土样品的水力传导率的不利影响最小化。研究结果表明，橄榄石可用作降低易开裂土壤的水力传导率的合适添加剂。这些改进归因于微结构分析证实的铝酸铝水合物凝胶和硅酸镁水合物凝胶的形成。凝胶负责使裂纹对处理过的粘土样品的水力传导率的不利影响最小化。研究结果表明，橄榄石可用作降低易开裂土壤的水力传导率的合适添加剂。这些改进归因于微结构分析证实的铝酸铝水合物凝胶和硅酸镁水合物凝胶的形成。凝胶负责使裂纹对处理过的粘土样品的水力传导率的不利影响最小化。研究结果表明，橄榄石可用作降低易开裂土壤的水力传导性的合适添加剂。