Air Permeability of Compacted Cohesive Soils

Air permeabilities of five compacted cohesive soils are determined by constant head and falling head methods. Dynamic, static, and kneading compaction methods, and different energy inputs are used for the preparation of the samples. The apparatus and testing procedure are described and the formula for data analysis is presented. Test results are presented to show the interrelationships among water content, compaction method, thixotropy, and air permeability. Deviations from Darcy's law are observed for the soils studied with apparent threshold gradients observed in essentially all tests. It is concluded that the air permeability characteristics of the compacted cohesive soils are affected by water content, dry density, compaction method, and thixotropy.