Model for soil-water characteristic curve considering grain-size distribution and deformation of soils

The particle-size distribution (PSD) of soils has been widely used in the estimation of soil-water characteristic curve (SWCC), and the pore-size distribution (POSD) of soils has an important effect on the SWCC, and the relationship between PSD and POSD is of great significance for the study of SWCC. Through the analysis of a large amount of experimental data, it is shown that there is a linear "ladder" distribution law between particle size and pore size in the double logarithmic coordinates, and the larger the particle size is, the more obvious the linear "ladder" is; the smaller the particle size is, the "ladder" disappears gradually and tends to linear distribution. The smaller the particle size, the "ladder" gradually disappears and tends to linear distribution. Based on this, firstly, the relationship between particle size and pore size is established according to the linear "step" distribution law; secondly, according to the Young-Laplace equation, the particle-size distribution function and pore ratio are introduced to establish a SWCC model considering the particle-size distribution and deformation of soils. Finally, the model is verified through several sets of experimental data, and the results show that all the proposed models in this study can conform to the experimental observations better, which verifies the reliability of the model.