轨道刚度对路轨系统及饱和地基动力响应的影响

Effect of rail rigidity on track-ground vibration due to a high-speed train

研究了轨道刚度对高速移动列车荷载作用下铁路系统动力响应的影响。将钢轨简化为无限长弹性Euler梁,将枕木简化为连续质量块,同时考虑道渣层的影响。由Fourier变换求解多孔饱和固体的动力基本方程,在Fourier变换域内,联立铁路系统和下卧土体的动力方程,求解列车荷载作用下钢轨位移、加速度、土体位移、孔压表达式。利用数值积分方法对表达式进行Fourier逆变换,得到钢轨位移、加速度、孔压在时域内的表达式。算例中主要讨论了荷载移动速度和轨道刚度对钢轨速度、加速度及土体孔压的影响。结果表明,轨道刚度在低速情况下对路轨系统和土体动力响应有影响较小,但在高速情况下对路轨系统和土体动力响应影响很大。

An analytical approach was used to investigate the effect of the rail rigidity on track vibration due to a high speed moving train. The rails were described by introducing the Green function for an infinitely long Euler beam, the sleepers were represented by a mass, and the ballast was placed under the sleepers. By employing the double Fourier transforms, the governing equations of motion were solved in the frequency-wave-number domain. The time domain responses were evaluated by the inverse Fourier transform computation. It was shown that dynamic responses of the soil medium were considerably affected by the rail rigidity when the velocity of train was high.