The vibration of railwayballa st is a keyfact or to cause track geometrych ange and increase of track maintenance costs. So far the methods for analyzing and testing the vibration of the granular ballast havenot been well formed. In this paper, a five-parameter model for analysis of the ballast vibration isestablished based upon the hypothesis that the load-transmission from a sleeper to the ballast approximatelyco incides with the cone distribution. The concepts of shear stiffness and shear damping of the ballast are introduced in the model in order to consider the continuityof the interlocking ballast granules. A full-scale field experiment is carried out to measure the ballast acceleration excited bymoving trains. Theoretical simulation results agree well with the measured results. Hence the proposed ballast vibration model has been validated.

The effect of a scratch formed on the running surface of a curved rail, due to the slide of a locomotive wheel, on the formation and evolution of rail corrugation is investigated in detail with numerical methods when a wheelset is steadily and repeatedly curving. In the calculation we consider a combination of Kalker’s rolling contact theory with non-Hertzian to be modified, a linear frictional work model and a vertical dynamics model of railway vehicle coupled with a curved track. Also the influence of different speeds of wheelset curving through the scratch on the development of the corrugation is taken into account. The numerical results indicate that a scratch causes strong contact vibration between the wheel and rail, and initiation and development of rail corrugation under the condition of steady creepage occurring between the wheel and curved rail. The wave-length of the corrugation depends on the speed of wheelset curving and the natural frequencies of the track.

The effect of track irregularities on rail corrugation is investigated in detail with the numerical method when a wheelset is steadily curving.The irregularities considered in the analysis include initial running surface of rail with periodically varying and different wave length, stochastic roughness on the rail running surface, and vertical uneven support stiffness of the rail due to the discrete sleeper supports.The numerical method considers a combination of Kalker’s rolling contact theory with non-Hertzian to be modified, a linear frictional work model and a vertical dynamics model of railway vehicle coupled with a curved track. The model is also validated by an experiment with a full scale facility.The influence of different speeds of wheelset curving on the development of the corrugation is taken into account in the calculation.The numerical results indicate that (1) for existing of the initial corrugation of new rail with any wavelength the depth from the peak to trough of it decreases gradually with an increase of wheelset passage, but the initial corrugation evolved has a tendency to move in the rolling direction, (2) the amplitude of the initial stochastic roughness of new rail is gradually leveled out and but a corrugation with very small depth and a few fixed passing frequencies is initiated, the passing frequencies are the same as the natural frequencies of the track, and (3) the discrete rail supports by sleepers have a great influence on the formation of the corrugation.

基于系统工程思想，运用频域分析方法。对轨道结构随机振动特性进行仿真计算与分析，并结合铁路现场测试结果对理论计算结果进行试验验证。结果表明：钢轨振动能量主要集中在1300Hz附近，而中、低频率的振动主要体现为轨枕与道床的振动；在整个分析频域范围之内，仿真计算得到的轨道结构振动加速度功率谱密度与试验测试结果吻合较好，且轨道结构振动加速度平均值的计算与试验结果差异不大。

基于系统工程思想，运用机车车辆一轨道耦合动力学理论，对采取了强化技术对策后的山区铁路小半径曲线轨道的动力性能进行仿真计算，并与强化前轨道结构动力学性能进行了对比分析。分析结果表明：强化后轨道结构的轮轨动态相互作用力及轨枕支点压力均较强化前的相应值略大，但皆属相同安全合格等级；强化轨道结构位移大幅度降低，有效抑制轨道结构变形，增强线路稳定性，尤其是钢轨横向位移和轨距动态扩大量较强化前下降十分显著，前者仅约为后者的1/3左右；强化轨道也有利于降低轨下结构振动和减轻列车提速后对轨下基础的破坏。