ABSTRACT
A three-dimensional elasto-plastic model for unsaturated soil is presented, using a transformed stress tensor based on the Extended SMP criterion. The influences of suction on the mechanical behavior of unsaturated soil are taken into account in the model by using a parameter named as suction stress σ 0(s), which is added to net stress to form an effective stress, and associating a yield stress and model parameters with suction through σ 0(s). The prediction of the proposed model shows good agreement with the measured behavior of unsaturated soil in various stress conditions under the conditions of constant suction and reduction in suction, which may induce collapse.
