Dynamic stability model and analysis of mechanical properties for railway operations

Dynamic track stabilizers have been widely used in the maintenance of ballast track, but limited studies have been carried out for the theoretical analysis of track stabilizing operations. In the present study, the structure of ballast track is innovatively established using bi-directional coupling modeling method which include discrete element method and multi-body dynamics method. The model is verified by field experimental data. Based on the tamping operation model, the mechanical properties of the ballast bed after tamping are obtained. Later simulation analysis of stabilizing operation is carried out to explore the change rule of sleeper displacement, particle contact, compaction, resistance and support stiffness of ballast bed. The results show that stabilizing operation can force the sleeper of the new railway line to move down quickly by 5.56 mm. The most significant improvement to the average coordination number between ballast was in the top layer of the crib area, which increased by 19.3%. The most significant area for improving the compactness of the ballast bed is the uppermost layer at the bottom of a sleeper, with an improvement rate of 6.4%. After stabilizing operation, the longitudinal and lateral resistances and supporting stiffness of the ballast track increased by 45.1%, 37.9% and 172.0%, respectively.