Abstract: The suction of coastal unsaturated saline soil at Huanghua Port with varied salt content and moisture content was studied via filter paper method. The soil-water characteristics together with the relationship between salt content and suction was examined, and the influencing factors and change rules of suction were analyzed. Moreover, the mathematical models of matric suction against volumetric water content, and osmotic suction against salt content and volumetric water content were established by fitting. Results revealed that the change of salt content had a great influence on total suction and osmotic suction. An exponential relationship was found between matric suction and volumetric water content. The model of osmotic suction against salt content and volumetric water content is of high goodness of fit.

Key words: saline soil, filter paper method, salt content, total suction, osmotic suction, matric suction, volumetric moisture content