Elastoplastic framework for the volumetric behavior of unsaturated soils

This paper proposes an elastoplastic framework to account for the volumetric behavior of unsaturated soils on the basis of the effective stress approach. The assumed effective stress is based on Bishop's equation where parameter chi is determined from a porous-solid model able to simulate the retention curves of soils during wetting-drying cycles. The numerical results of the proposed elastoplastic framework are compared with experimental results published in the international literature. These comparisons show that this framework is adequate to account for net stress loading under different values of suction. In addition it results in a unifying theory for both saturated and unsaturated materials.