عنوان مقاله [English]
Concrete sleepers in railway track are installed on ballast and subgrade to transfer train wheel loads to subgrade. 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 response. This paper presents influence of ballast voids on vibration responses in two shapes of numerical and finite element model. Investigation of influence impact patterns between ballast and sleeper can present guidance's for ballast tracks designers and engineers in the field age and mode of cracking of concrete sleeper in the vibration which is near to resonance frequency.