Load Impact on Railway Track Due To Unsupported Sleepers

This paper investigates the dynamics of a railway track with hanging sleepers. A computer model by which the dynamic train/track interaction can be simulated is presented, and the influence of one or several unsupported (voided) sleepers on the train/track interaction force and on the track dynamics is investigated. Ballasted railway tracks will settle as a result of permanent deformations in the ballast and in the underlying material layers. The settlement is caused by the repeated traffic loading and the amount of settlement will differ from one sleeper to another since the behavior of the material is not exactly the same under all sleepers and since the loading of the track is irregular. As a result, the sleepers are not always fully supported and some sleepers may even become completely unsupported (voided). A gap appears between the sleeper and the ballast bed. As soon as the track geometry starts to deteriorate, the variations of the train/track interaction force increase, and this speeds up the track deterioration rate. Findings from this study indicate that one single hanging sleeper with a 1 mm gap between sleeper and ballast can cause the sleeper/ballast contact force at the sleeper adjacent to the hanging one to increase by 70%. The displacement of the sleeper adjacent to the hanging one will increase by 40%. The uneven loading of the ballast bed may induce an irregular settlement of the track bed. An increase in speed will give higher contact forces between the sleepers and the ballast, and will give larger deflections and stresses in the sleepers following the unsupported sleepers.


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  • Accession Number: 01003989
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 19 2005 11:54PM