冻胀变形下高速铁路车辆-轨道-路基耦合系统的动力效应

Dynamic Effect of High Speed Railway Vehicle-track-subgrade Coupling System under Frost Heaving Deformation

季冻区严酷的自然环境对高速铁路的高标准运行产生了极大影响,甚至会对高速铁路造成永久性破坏。为探究季冻区高速铁路路基冻胀变形作用下对车辆-轨道-路基耦合系统动力效应的影响,以银西高速铁路某冻胀区段为背景,结合车辆-轨道-路基系统动力学的原理和分析方法,建立了简化后的动力学模型;选取了典型的单波余弦冻胀波形(冻胀波长λ=10 m,冻胀峰值f=10 mm),分别探讨了轨道系统与车辆系统的动力学效应,并据此确定了轨道刚度的合理取值。研究结果表明:在路基冻胀变形作用下,轨道系统中轨道各部件动压力、动位移及动加速度幅值在低频段(0~200 Hz)发生明显波动,扣件刚度与道床刚度的最优刚度比为0.5,轨道总刚度的合理取值在62~87 kN/mm范围为宜;车辆系统中车辆轮重减载率及车体垂向加速度与冻胀波长λ成反比关系,与冻胀峰值f成正比关系。

The harsh natural environment in the seasonally frozen area has a great impact on the high-standard operation of the high-speed railway,and may even cause permanent damage to the high-speed railway.To explore the influence of frost heave deformation of high-speed railway subgrade in seasonally frozen areas on the dynamic effect of vehicle-track-subgrade coupling system,a frost heave section of Yinxi high-speed railway was taken as the background,combined with the principle of vehicle-track-subgrade system dynamics and analytical methods,a simplified kinetic model was established.Moreover,a typical single-wave cosine frost heave waveform(frost heave wavelengthλ=10 m,frost heave peak value f=10 mm)was selected to discuss the dynamic effects of the track system and the vehicle system respectively,and based on this,a reasonable value of the track stiffness was determined.The research results show that under the action of subgrade frost heave deformation,the amplitudes of dynamic pressure,dynamic displacement,and dynamic acceleration of the track components in the track system fluctuate significantly in the low-frequency band(0~200 Hz).The optimal stiffness ratio of the fastener stiffness to the ballast bed stiffness is 0.5,and the reasonable value of the total track stiffness is in the range of 62~87 kN/mm.In the vehicle system,the vehicle wheel load shedding rate and the vertical acceleration of the vehicle body are inversely proportional to the frost heave wavelengthλ.They are directly proportional to the frost heave peak value f.