Effect of Irregular Shape and Cyclic Loading Frequency on the Dynamic Behavior of Railway Ballast

Higher speed in existing railway transportation is underlying growth in demand and the meso-mechanical properties of ballast under high-frequency loading. The complex geometry of ballast has influences on their dynamic behavior inevitably. Thus, a numerical polyhedral discrete model based on real irregular shape of ballast triaxial test was established to investigate the combined effect of shape and frequency on the dynamic behavior of ballast. Experimental results of large-scale triaxial tests were used to determine and verify the meso-parameters of the discrete-element model. With same axle load and confinement, three cases of different ballast shapes (i.e., quasi-spherical, elongated and flat, respectively) under different load frequency f (2.4, 5, 10 and 30 Hz) were discussed. Results obtained from models show that the irregular shape has a significant influence on the accumulated deformation of grains. Although the gradation of three specimens was similar, their dynamic response had obvious differences. Contact forces between loading plate and ballast of varied shapes were almost the same, but the increasing load frequency can make the accumulative deformation of the ballast sample to continue growing.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01898448
  • Record Type: Publication
  • ISBN: 9789811523489
  • Files: TRIS
  • Created Date: Nov 8 2023 3:51PM