The influence of operation times of manual tamping device on ballast bed state

Abstract

The manual tamping device plays an important role in the daily maintenance and repair of ballasted track. It is difficult to establish a suitable analytical model for manual operations because of their inherent flexible characteristics. There is a lack of sufficient theoretical research on daily maintenance and repair which are mainly based on the long-term field experience of workers. For guiding the field operation of manual tamping devices, a coupled simulation model of impacted manual tamping device and ballasted track was established based on the DEM-MBD coupling method. The proposed model effectively simulated the manual tamping operations. The correctness of the model was verified through field lateral resistance tests. The proposed coupling model was applied for computing the change in the support stiffness of the ballast bed under different tamping times. Further analysis was done to study the impact of manual tamping operations on the contact force and movement of the ballast. The results show that the vibration and impact of the manual tamping device have changed the original contact relationship between the ballast particles. The attenuation amplitude of the support stiffness of the ballast bed initially decreased and later increased with increase in tamping times, resulting in the ballast bed with higher initial stiffness more elastic. A similar trend and good synchronization were observed between the average contact force and angular velocity between ballast particles with manual tamping time, resulting in improved compactness and stability of the ballast bed. And it is recommended to perform tamping five times for optimal results.