Damage model for unsaturated structural loess under cyclic loading

Based on the boundary surface elastoplastic model, the cemented damage theory and the basic Barcelona model for unsaturated loess, an elastoplastic damage model for unsaturated loess under cyclic loading is proposed. Firstly, the law for bonds degradation is given, where the structure damage and the accumulation of absolute values of strain increments are combined. Then, the water-retention curve is employed to consider the coupling of suctions and stresses under constant water condition. Finally, triaxial tests under cyclic loading are carried out; the comparison between experimental results and model simulations shows that the proposed model is capable of describing mechanical behaviors of unsaturated loess under cyclic loading.