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An appropriate interface constitutive model is crucial to the simulation of soil-structure interface behavior. Currently, most models are only capable of describing the mechanical properties of rough interface. However, they are unable to simultaneously account for the effects of surface roughness and particle breakage. This study proposes an elastoplastic interface constitutive model considering the effects of normal stress, relative density, particle breakage, and surface roughness. It describes the variations of critical void ratio and critical stress ratio with normalized surface roughness by exponential functions. Change in critical void ratio caused by particle breakage is denoted by input work. An expression of the critical state line and a modified dilatancy function are derived based on the state-dependent dilatancy theory, uniformly describing the influences of relative density, particle breakage, normal stress, and surface roughness. The yield and hardening functions are introduced by including the plastic shear displacement as the hardening parameter based on the Mohr-Coulomb criterion. Finally, experimental data from the literature are utilized to validate the accuracy of the proposed model for various materials under different conditions.

来源平台：KSCE JOURNAL OF CIVIL ENGINEERING