Unsaturated weathered soils are frequently encountered in most areas of Korea during construction works. Nevertheless, studies on unsaturated soils have been seldomly conducted. Soil water characteristic curve is the important property in the unsaturated soils. Indirect estimation of this property using easily measurable soil properties remains the research focus of many soil scientists. However the applicability for the Korean weathered soils has not been verified.
In this study, a general approach was proposed to derive soil water characteristic curve from soil particle-size distribution and bulk density using modified Arya & Paris model. Arya & Paris model is an indirect method to estimate the soil water characteristic from the particle-size data. In modified Arya & Paris model, two fitting parameters are used to make applicability higher. The fitting parameters are related to the soil properties.
For the unsaturated soils sampled in Seochang, Okchun, Chochiwon, Yeongi, and Asan areas, soil water characteristic curve can be obtained by plotting the test results. The results can be compared with the results of Arya & Paris method.
From the compared results, the trends of fitting parameters are analyzed, and appropriate functions of fitting parameters which can be applicable for Korea weathered unsaturated soil are proposed.
