钢轨波磨对无砟道床动态响应的影响

Influence of Rail Corrugation on Dynamic Response of Ballastless Track Bed

为掌握无砟道床在钢轨波磨影响及损伤条件下的动态响应,建立了高速铁路钢轨波磨对轨道板和CA砂浆动态响应的影响评价模型。利用车辆-轨道垂向耦合动力学获取高速列车通过钢轨波磨区段时的扣件力,并将其作为可考虑层间离缝的无砟轨道有限元模型的初始激励,计算了高速列车通过波磨波长60~160 mm、谷深5~100μm钢轨时轨道结构的振动响应。结果表明,钢轨波磨导致扣件、轨道板和CA砂浆的动态响应出现高频波动,其频率与波磨通过频率一致;钢轨波磨波长主要影响轨道系统的激励频率;随着钢轨波磨谷深的增大,无砟道床动态响应先缓慢增大,超过40μm后迅速增大,计算结果分析得到的波长与谷深影响规律与最新的钢轨打磨标准一致;层间存在离缝时无砟道床动态响应受波磨的影响更显著,使轨道板离缝进一步扩展,且易导致CA砂浆层碎裂伤损等病害。

In order to master the dynamic response of ballastless track bed under the influence of rail corrugation and damage conditions,an evaluation model for the influence of rail corrugation on the dynamic response of track slab and CA mortar of high-speed railway was established.Using the vehicle-track vertical coupling dynamics,the fastening force of the high-speed train passing through the rail corrugation section was obtained,and it can be taken as the initial excitation of the finite element model of ballastless track considering the interlayer separation joint.The vibration response of the track structure was calculated when the high-speed train passes through the corrugation rail with the wavelength of 60~160 mm and the valley depth of 5~100 m.The results show that rail corrugation leads to highfrequency fluctuations in the dynamic response of fasteners,track slab and CA mortar,and its frequency is consistent with the passing frequency of corrugation.The rail corrugation wavelength mainly affects the excitation frequency of the track system.With the increase of rail corrugation valley depth,the dynamic response of ballastless track bed first increases slowly and increases rapidly when the depth is more than 40μm,the influence law of wavelength and valley depth obtained from the analysis of calculation results is consistent with the latest rail grinding standard.When there is separation between layers,the dynamic response of ballastless track bed is more significantly affected by corrugation,which intensifies the further expansion of the separation of track slab,and easily leads to such diseases as fragmentation and damage of CA mortar layer.