Many natural soils (e.g. glacial tills, residual soils and alluvial soils) and artificial soils (e.g. engineered fill and environmental barriers) are composite soils formed of a range of particle sizes and types. These soils are often difficult to sample and test when following standard site investigation practice; thus, it is necessary to resort to empirical correlations, most of which were developed for either coarse-grained (e.g. clean sands) or fine-grained soils (e.g. pure clays). The hydraulic conductivity of clean sands is a function of the void ratio and particle size distribution, and for clays, of the clay type and void ratio. This suggests that the hydraulic conductivity of composite soils will be a function of these properties and the clay content. Composite soils formed of four clay minerals and two sands were consolidated from slurry to determine the variation in hydraulic conductivity with clay content, clay type and void ratio. With matrix-dominated soils, soils that have more than 35% fines content, the flow is a function of the matrix void ratio and clay type; and for clast-dominated soils, soils that have less than 20% fines content, the intergranular void ratio and particle size distribution. The behaviour of soils with a fines content between 20 and 35% depends on the confining pressure and density.

中文翻译：

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复合土的渗透性

许多天然土壤（例如冰川耕地，残留土壤和冲积土壤）和人工土壤（例如工程填料和环境屏障）是由多种粒径和类型组成的复合土壤。按照标准的现场调查实践，这些土壤通常很难取样和测试。因此，有必要诉诸经验相关性，其中大多数是针对粗粒（例如干净的沙子）或细粒土壤（例如纯粘土）开发的。清洁砂的水力传导率是空隙率和粒度分布的函数，而对于粘土，则是粘土类型和空隙率的函数。这表明复合土壤的水力传导率将是这些特性和粘土含量的函数。用泥浆固结由四种粘土矿物和两种砂形成的复合土，以确定水力传导率随粘土含量，粘土类型和孔隙率的变化。对于基质占主导的土壤，即细粉含量超过35％的土壤，流量是基质空隙率和黏土类型的函数。对于以碎屑为主的土壤，其细粉含量，晶间空隙率和粒度分布小于20％的土壤。细粉含量在20％至35％之间的土壤的行为取决于围压和密度。细粉含量，粒间空隙率和粒度分布小于20％的土壤。细粉含量在20％至35％之间的土壤的行为取决于围压和密度。细粉含量，粒间空隙率和粒度分布小于20％的土壤。细粉含量在20％至35％之间的土壤的行为取决于围压和密度。