A comparative study of soil water retention curves by the evaporation test with other experiments for Korean residual soil

The soil water retention curves(SWRCs) were acquired by experiments based on the evaporation method and compared with the result of volumetric pressure plate and chilled mirror tests for five samples in Korean residual soils. Under 100kPa suction, the SWRCs by the evaporation test agreed with those of volumetric pressure plate tests in the axis of effective saturation for five samples. In two samples, initial values of water content have shown 6% of difference, which doesn’t affect the fit of SWRCs. In the higher suction, the SWRCs were measured rapidly by chilled mirror tests. The SWRCs were fit efficiently  from low to high suction by both the evaporation and the chilled mirror tests. It is found that the fit only by low suction data couldn’t the actual SWRC accurately. Using the result of the current SWRCs and other data, the DB has been constructed and the parameters of the van Genuchten fit were interpreted. It was found that Korean residual soils are classified by three soils based on the range of void ratios.

Acknowledgements This research is supported by grant from Korean NRF (2019003604), which are greatly appreciated.