Abstract: The particle breakage of rockfill materials is one of the significant factors influencing the deformation behavior of rockfill high dams. The stress paths and saturation of rockfills vary during the process of construction and impoundment. A series of large-scale triaxial tests was systematically conducted to investigate the influences of stress paths and drying-wetting states on particle breakage behaviors. The results show that the particle breakage index under different stress paths is not the same for the same axial strain. The particle breakage index of the constant ?3 test is larger than that of the constant p test and the particle breakage index of constant ?1 test is the least in the three stress paths. The particle breakage index of saturated specimen is higher than that of the dry one with the same initial condition and the gap increases with the confining pressure. The evolution of particle distribution under different stress paths and saturation states is the same. The established relationship between particle breakage index and plastic work considering the strength of the parent rock can well unify the particle breakage index under different stress paths and saturation states. The results can provide valuable references for the elastic-plastic constitutive model considering the particle breakage under complex stress paths and dry and wet conditions.

Key words: rockfill material, stress path, saturation states, particle breakage, triaxial test