Minimizing breakage and optimizing ballast reusability during excavation for ballast cleaning: A computationally efficient model and operational parameter recommendations

During the excavation for ballast cleaning, intense interactions result in ballast breakage and damage. This reduces both the reusable mass and the mechanical properties of excavated ballast. Given the high rate of ballast breakage, existing breakable ballast models suffer from low computational efficiency and struggle to account for the accumulation of internal damage in particles. Thus, we introduced a computationally efficient breakage model that considers cumulative damage. This model was tested through experiments to simulate ballast behavior. The discrete element and multibody dynamics coupling methods were employed to develop a model that integrates an excavation device with a ballasted track. Utilizing this coupled model, we investigated the behavior of ballast breakage, the reusability of excavated ballast, and the impact of various operational parameters. These findings revealed that approximately 60 % of the ballast experienced breakage. However, such breakage can be mitigated by controlling the mass of excavated ballast. Theoretical excavation and rake-chain velocities were recommended to optimize excavation efficiency while minimizing breakage and improving the reusability of excavated ballast. This study can provide insights into enhancing the quality of ballast cleaning and reducing maintenance costs.