Influence of Ballast Voids on Dynamic Responses of Concrete Sleepers

The concrete sleeper that is one of the major part of ballast railway tracks are installed on ballast and subgrade to transfer any train wheel loads to the ground support subgrade in operation period that a wide range of loading conditions has been observed. In most of the cases, train wheel impact loads due to asymmetrical cause voids and pockets in contact interface of sleeper and ballast. When the ballast was damaged, the stiffness in ballast supporting of the sleeper will reduce. Voids of ballast can effects in-suit sleeper vibration responses. In order to analyses finite-element can model free – free and in suit sleeper with using 50 Timoshenko beam elements with a trapezoidal cross-section while the rail pads and the ballast system were modeled using a spring damper element and the elastic beam support feature in STRAND7,accordind to fig.1.