Identification and application of track irregularity power spectrum of a new subway line

In order to analyze the characteristics of track irregularity power spectrum of a newly built subway line, firstly, based on the measured line data, the power spectrum of vertical irregularity is estimated by the Welch method, and compared with the standard spectrum at home and abroad. Then, the seven-parameter model is used to fit the subway track spectrum in the wavelength range of 2.5~30m. Finally, the inverse Fourier transform is used to simulate the track irregularity time domain sample sequence. The results show that the track irregularity quality of the new subway line is excellent. The seven-parameter model can follow the trend of the track spectrum very well, and the goodness of fit is 0.9875. The amplitude and power spectrum curves of the simulated samples are close to the measured data. The research results can provide support for the dynamics simulation of subway vehicles.