A theoretical retention model for unsaturated uniform soils

The present study focuses on a theoretical model for unsaturated soils based on elastic spherical particle arrangement, which can be considered to be a simplified Discrete Element Method. As a first step, a uniform model is introduced with a single soil particle diameter. This approach follows a new research methodology so that the physical relations between soil particles, interstitial water and air are used. With such a model, the number of experimental parameters needed will be limited. The theoretical model takes into account the different arrangement of soil particles so that the entire voids ratio scale is covered. The wetting and drying paths are modelled. A comparison with previous theoretical model and the proposed new theory is achieved on experimental results with two uniform glass samples. It shows that this new theory improves the precision of the prediction, using only simple physical parameters.