高速铁路双块式无砟轨道车辆荷载动态传递特征

Dynamic transfer characteristics of vehicle load on double-block ballastless track of high-speed railway

摘要:

为研究车辆荷载在无砟轨道中的传递特征,建立车辆-双块式无砟轨道耦合动力学模型,对车辆荷载在无砟轨道主体结构内的动应力和振动加速度传递规律进行研究,并对行车速度、结构尺寸及层间接触状态等影响因素进行分析. 结果表明:车辆荷载的主承载区分布在道床板内,垂向动应力峰值在0.1 m深度之内衰减73%；车辆荷载的主振动区主要分布在道床板内并传递至支承层,垂向加速度峰值在0.1 m深度之内衰减89%；轨道结构动态受力及振动响应均随行车速度的增加而增大；适当减少轨道结构宽度,对其受力和振动特性影响较小. 无砟轨道结构层间插入隔离层,可减小轮轨动力响应及轨道结构动态受力,但结构层间垂向加速度明显增大,插入弹性层,可减小钢轨垂向加速度,但对轮轨动力响应、道床板和支承层动态受力及振动特性影响较小. 所得结论可为无砟轨道设计和优化提供理论参考.

Abstract:

To study the transfer characteristics of vehicle load on ballastless track, a vehicle-double-block ballastless track coupling dynamic model was established. The transfer law of dynamic stress and vibration acceleration of vehicle load in the ballastless track was investigated, and the influencing factors were analyzed, such as driving speed, structural size, and interlayer contact state. Results show that the main load-bearing area of the vehicle load was distributed in the bed slab, and the peak value of vertical dynamic stress was attenuated by 73% within the depth of 0.1 m. The main vibration area of the vehicle load was mainly distributed in the bed slab and transmitted to the supporting layer, and the peak value of vertical acceleration was attenuated by 89% within the depth of 0.1 m. The dynamic force and vibration response of the track structure both increased with increasing driving speed. When the width of the track structure was appropriately reduced, the force and vibration characteristics were less affected. By inserting the isolation layer between the structural layers, the dynamic response of the wheel-rail and the dynamic force of the track structure were reduced, but the vertical acceleration between the structural layers was obviously increased. Inserting the elastic layer could reduce the vertical acceleration of the rail, but the dynamic response of the wheel-rail and the stress and vibration characteristics of the bed slab and supporting layer were less affected. The results can provide theoretical reference for the design and optimization of ballastless track.