Abstract: K0 compression tests and constant stress ratio path tests were performed on three kinds of coarse-grained soils in conventional consolidated-drained (CD) triaxial tests. Parameters of unified hardening (UH) model were calibrated according to the triaxial test data, and then stress-strain relationships under the other two paths were simulated. The simulation results were compared with those obtained from Duncan’s E-B model. It is shown that UH model can reasonably describe the mechanical behaviors of coarse-grained soil under different stress paths, while Duncan’s E-B model behaves poorly in predicting the results. The applicability of UH model to coarse-grained soil has been verified. Finally, three-dimensional finite element analysis of stress and deformation for a core rockfill dam was performed by using UH model. The calculation results were compared with those of Duncan’s E-B model and the field monitoring data. It is shown that from a qualitative perspective of the distribution of dam deformation and stress, the results obtained from UH model are similar to those from Duncan’s E-B model. However, from a quantitative perspective, the deformation calculated from UH model is overall closer to the field monitoring data. The applicability and rationality of UH model in the field of earth rockfill dam have also been verified.

Key words: coarse-grained soil, UH model, Duncan’s E-B model, K0 compression test, constant stress ratio path test, earth rockfill dam