Abstract: To predict the cumulative plastic deformation characteristics of ballasted tracks under contaminated conditions, we utilized cyclic loading triaxial tests and a revised subloading surface model to investigate the cumulative plastic deformation characteristics of fouled ballast under cyclic loading. The findings revealed a synergistic effect of fine fraction content and moisture content on the hydro-mechanical properties of ballast. Particularly, simultaneous increases in fine fraction content and moisture content lead to a continuous decline in the mechanical properties of ballast, exacerbating the cumulative settlement of railway ballast under cyclic loading. Additionally, a modified subprogram for the subloading surface model was developed based on its constitutive theory and finite element software. The model’s validity was confirmed through comparison with results from cyclic loading triaxial tests. Numerical simulations demonstrated that the proposed model effectively predicts the evolution of cumulative plastic deformation of railway ballast under varying moisture and fine fraction content. Hence, the revised subloading surface model can be applied in future studies to establish a comprehensive engineering analysis model for predicting the long-term settlement of railway tracks under different fouled conditions.

Key words: railroad ballast, moisture content, fine fraction content, triaxial test, revised subloading surface model