Effect of Compactness Degree on the Hydraulic Properties for Coarse Soils of High-Speed Railway Embankment

Stability of the high-speed railway embankment is highly influenced by moisture content, the determination of which needs its hydraulic property. The embankment consists of coarse soils with high compactness degree. Till now, hydraulic properties of such coarse soils are not fully studied. In this article, a large scale column, which could measure the volumetric water content and suction, was adopted to study the hydraulic properties of three types of coarse soils. The compactness degrees of soil samples were 0.85, 0.90 and 0.93 respectively. The soil-water characteristic curves (SWCCs) could be gained directly and the hydraulic conductivities could be calculated through instantaneous profile method. The SWCCs and unsaturated conductivities of different soils were presented and compared. The results showed that compactness degree had an influence on SWCC (e.g., the air-entry value, the slope and the residual matric suction) and the unsaturated permeability.