In order to suggest a procedure for estimating the generalised soil-water characteristic curves of natural soils, modified pressure cell extractor tests were carried out on soil specimens at various void ratios, which were compressed from liquid limit state. The main conclusions from this study are summarised below: (a) The modified pres sure cell extractor allows determination of the soil-water characteristic curves of deformable soils. The compression and unsaturation processes can be performed in succession using the same cell, so specimen disturbance can be avoided. The volume change of deformable soils can be measured directly. (b) The residual soils used in this study showed significant volume change due to matric suction. The soil-water characteristic curves corrected for volume change have higher air-entry values, flatter slopes, better correlation, and a narrower gap among themselves, compared with the uncorrected curves. These results highlight the importance of volume change correction when soil-water characteristic curves are obtained in deformable soils. (c) For the residual soils used in this study, the normalised constituent parameters of soil-water characteristic curves have a linear relationship with the normalised void ratio, showing the validity of the reference state approach in estimating soil-water characteristic curves for natural soils. Finally, an empirical procedure was provided for the estimation of generalised soil-water characteristic curves using liquid limit state as a reference state.
- Soil/structure interactions
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Earth and Planetary Sciences (miscellaneous)