Ballast Vibrations and Deformations due to Different Train Loading Scenarios Studied Using the Discrete Element Method

摘要

This paper focuses on the effects of different dynamic train loading patterns on the vibra -tion and permanent deformation r accumulation trends of railroad ballast. As opposed to a continuous sinusoidalload pulse often applied in cyclic triaxial r tests ,the actual dynamic train loading may have loading patterns of varying pulse shapes with rest periods. A validated r ballast model, based on the Discrete Element Method and imaging based aggregate size/shape characterization ,was used to r simulate both continuous sinusoidal and moving wheel loading patterns of different train loading speeds or frequencies with r and without rest periods between loadpulses. The continuous sinusoidal loading resulted in larger ballast layer settlements r in DEM simulations when compared to a more realistic moving wheel dynamic loading pattern that considered rest periods.