Triaxial repeated load saturated drained compression and extension tests at low cell pressures on a fine mineral grained tough dolomite railroad ballast are reported. Both plastic strains and ballast breakdown were found to be related to the stress difference factor cycled. This may be associated with track improvement due to higher factors of safety with respect to the tie-ballast interaction and thus broader ties and a smaller spacing-breadth ratio. Cycling the stress difference also caused a stiffening of the ballast confirming the practice of using trains subject to slow orders to further compact ballast in track after maintenance. In the extension repeated load tests failure was observed at stress difference factors of 0.5 confirming the problems of track lateral instability associated with curves and the importance of regular maintenance where lateral track forces are high.

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Filing Info

  • Accession Number: 00182587
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Oct 12 1978 12:00AM