Soil-water characteristic curve of quasi-saturated compacted soil

Important geotechnical structures involve cohesive soil compacted either around or on the wet side of optimum water content. In general, at these water content values, water component in soil voids is continuous but the air phase is not. The soil with entrapped air may be assumed to be in a state termed as "quasi-saturated". The soil-water characteristic curve (SWCC) is often used to estimate various unsaturated soil parameters. Since the measurement of pore-air pressure in an occluded sample is extremely difficult, the data for the SWCC for quasi-saturated soils is not well-defined. A new and relatively simple equation for the soil-water characteristic function for quasi-saturated soils is derived using the theory proposed by Schuurman (1966). The equations parameters are physically meaningful and can be easily determined. Experimental results show that the proposed soil-water characteristic function is reasonably accurate.