An advanced constitutive model for drained and undrained unsaturated soil under different over-consolidation ratios

Abstract

The soil deposits for general constructions and mining are often under both saturated and unsaturated conditions at different overconsolidation ratios. Within the frameworks of the unified hardening unsaturated model, in this paper, a constitutive model is proposed for the unsaturated overconsolidated soil under drained and undrained conditions. This model is validated against the unsaturated experimental results, and the hydromechanical behavior of soil is thoroughly investigated considering the dilation behaviour under a high overconsolidation ratio. It is found that the prediction results for the volume change, deviator stress, and suction behavior determined by the proposed model agree well with the experimental results, particularly for the dilation behaviour. It can be concluded that this model can predict the hydromechanical behavior of the unsaturated overconsolidated soil under both the drained and undrained conditions.