Based on the finite element model, the vertical natural frequency of subgrade was obtained through the modal analysis of the subgrade transition section of Wu-Guang (Wuhan-Guangzhou) High-speed Railway. The time history of vibration and damped free vibration waveform of the subgrade were acquired by ambient excitation and train loads excitation, and the nature frequency was obtained through principle of Fourier transform and maximum entropy spectrum method. The result of modal analysis was chosen in actual measurement. The results show that the model is correct and the natural frequency of the...
