Spatial Distribution Characteristics of Displacement of Heavy Haul Railway Ballasted TrackSubgrade System Under 30 t Axle Freight Vehicle Running

Abstract:

A dynamical interaction model of the ballasted track, subgrade and heavy haul train system was developed. The distribution of displacement of the heavy haul railway ballasted Tracksubgrade system under 30 t axle freight vehicle running are solved using the combination of the new rapid explicit integration method and the Newmark integration method. The results show that the dynamical displacement state of each structure layer of the tracksubgrade system is complex, and the load is in the cyclic loading and unloading during heavy haul vehicle passing. The amplitude of vertical dynamic displacement is the largest in three components of the displacement of the tracksubgrade system, while the amplitude of the lateral displacement and longitudinal displacement are less than 6% of the amplitude of the vertical dynamic displacement. The dynamic displacement distribution in lateral direction, of which the amplitude fluctuation is less than 0.2 mm, is relatively moderate and could be approximated as uniform distribution. The changes of the dynamic displacement of the tracksubgrade system in vertical direction could be divided into three phases: for the first part between the rail and the sleeper, the amplitude of dynamic displacement attenuates distinctly; for the second part, the amplitude of dynamic displacement attenuates gently in the sleeper region; and for the third part under the ballast bed, the amplitude of dynamic displacement attenuates continuously along the vertical direction, and the rate of attenuation is continuously decreasing with the increase of the depth.