Macro–meso mechanical properties of ballast bed during three-sleeper tamping operation

Abstract

ABSTRACT The tamping operation is an effective means to quickly restore the status of the lines. The purpose is to explore the three-sleeper tamping operation mechanism maintenance. First, a model of the interaction between tamping picks and ballast particles was proposed. Then, the model of three-sleeper tamping operation was established by discrete element method (DEM) and multibody dynamics (MBD) coupling approach. Finally, the macro–meso properties of ballast particles was analysed. The results indicate that the tamping operation can considerably reduce the compactness of the ballast bed in the bottom of the sleeper and the crib area and also disturb the ballast shoulder area. In the penetration stage, there is a critical position of normal contact force of ballast particles. Moreover, the ballast at the bottom of the sleeper can move to either side of the sleeper during the rotation stage of the retracting, which is not conducive to the compaction.