Changes in Sediment Volume, Liquid Limit, and Plastic Limit of Alluvial Soils upon Drying

Several soils were slowly dried, and changes in sediment volume, liquid limit, and plastic limit of the soils with decreasing initial soil water content were investigated. For alluvial soils, sediment volume did not show appreciable changes unless the soils were dried to pF 4.2–4.5. Upon further drying, it decreased successively with falling initial soil water content. These results did not seem to depend on the organic matter content or drying history of the soils. Similar results were obtained for the liquid limit and plastic limit. It was considered that the significant changes in these physical properties upon drying beyond pF 4.2–4.5 were due to the decrease in the pore volume of soil-water systems through the formation of clay domains during the drying process.