Influence of dry density on the Soil-Water Characteristic Curve of compacted granite residual soils of Taishan section, Guangdong, China

Abstract

 The Soil-Water Characteristic Curve (SWCC) is a conceptual and interpretative tool through which the internal mechanisms and the behaviour of unsaturated soils can be understood. On the other hand, one important factor that affects the SWCC is the density. The main objective of this research is to evaluate the influence of dry density on the SWCC for different densities compacted granite residual soils collected from Taishan section, Guangdong, China based on laboratory experiments. In this study, the compacted granite residual soil samples are prepared at four different dry densities using different compaction efforts and the matric suction is measured by 15 bar pressure plate extractors. The results show that with the increasing dry density, the water-holding capacity of the soils decrease because of the overall pore volume reduced and the soil particles are drawn closer together. It also found that the VAN GENUCHTEN (1980) model fitting parameter , n and m are affected directly by the density and the relationship is linear. The air entry value increases with increasing density and uniform pore size distribution might be formed at higher density. Overall, the experimental results are capable of capturing hydraulic behavior of different densities compacted granite residual soils and might be used for practical purposes.