UH model for unsaturated soils

A new elasto-plastic model for overconsolidated unsaturated soils is presented by combining the Barcelona Basic Model (BBM), one of the classic elasto-plastic models for unsaturated soils, and UH model, one of the improved elasto-plastic models for overconsolidated soils, with the same soil parameters as the Cam-clay model. The proposed model is able to be changed into the UH model and BBM while the suction of overconsolidated unsaturated soils is zero and the consolidation behavior of unsaturated soils disappears respectively. Compared with the previous models, the wetting behavior of unsaturated soils in overconsolidated condition can be described more reasonably while many characteristics of overconsolidated soils considering suction effect can be modeled, including strain-hardening, softening, dilatancy and stress path dependence behavior. It is shown in the model that the overconsolidation level declines or even disappears during wetting. The validity of the model is confirmed by data from the previous triaxial tests for overconsolidated unsaturated soils.