Numerical Study on the Creep Size Effect in Rockfill Engineering

Laboratory tests are employed to analyze and predict the creep mechanical characteristics of field rockfill materials. However, these tests often underestimate the creep settlement and stabilization time in field rockfill projects, resulting in an inflated perception of the actual reliability of the engineering. To address this issue, this paper proposes a macro‐micro probabilistic integral creep model for rockfill materials that considers the size effect, dispersion, and time effect of particle strength, incorporating the delayed crushing of particles. The model is validated using the triaxial creep characteristics of limestone and granite rockfill materials. The differences in strength dispersion between laboratory and field rockfill materials are explained based on the weakest link theory. Subsequently, numerical analyses of the creep behavior of rockfill materials of various scales are performed using the proposed probabilistic integral method. The findings reveal that the deformation size effect of creep characteristics in rockfill materials is primarily influenced by the strength size effect, while the time size effect is predominantly driven by the strength dispersion.