Primary imbibition curve measurement using large soil column test

For analyzing unsaturated conditions of hydraulic and mechanic tests, the Soil Water Retention Curve (SWRC) is the most important information which should be experimentally measured. Therefore, the measurement of SWRC becomes the vital puzzle in the entire map for predicting unsaturated soil behavior regarding seepage, failure, and deformation. Standard SWRC test employs the standard Axis Translation Technique (ATT). However, beyond the primary draining path, it is extremely time-consuming to measure the primary imbibition curves with this device. In order to provide an alternative way for measuring the primary imbibition curve, two 2 m long sandy soil columns were set up with an advanced measuring technique for measuring water content profile. The results of this method are compared with measurements using the hanging column method providing observations in the lower suction range (0~20 kPa). The performance of this experimental setup is demonstrated with a discussion of advantages and disadvantages.