Validation of the direct measurement of the soil water characteristics curve using the newly developed continuous pressurization method

Natural disasters including earthquakes, typhoons and heavy rainfalls induce various risks such as slope failure. The soil water characteristics curve [SWCC] is a key index in unsaturated soil behavior used for estimating many unsaturated soil relations. Considering the complexity and prolonged time required for the conventional testing methods, a simple method that considers short time and high accuracy is still lacking. This paper aims at validating the newly developed continuous pressurizing method [CPM] apparatus by comparing it to the conventional axis-translation technique [Tempe cell] under drying phase. Standard soils in addition to remolded natural soils collected at earthquake and heavy rainfall induced landslides were used for validating the newly developed CPM device and investigating the CPM reliability, accuracy, repeatability and testing time in comparison to the conventional technique. It can be concluded that the newly developed CPM is an accurate with precise repeatability, reliable, direct and requires very short time SWCC obtaining method requiring 9 % to 17% of the testing time using the conventional method.