Response spectra of fitted post-seismic residual track irregularity for high-speed railway

Chinese high-speed railway (HSR) network construction has expanded into earthquake-prone areas. In this context, analyses of post-seismic residual track irregularity and post-seismic train speed threshold are vital. With a HSR bridge with track system taken as the study object, time-domain signal for target post-seismic residual track irregularity was constructed based on the Gaussian pulse translation theory. The response spectra of fitted post-seismic residual track irregularity applicable to stochastic structures were established, thus providing irregularity input for ascertaining post-seismic speed threshold. The results show that residual alignment irregularity has a large amplitude under transverse seismic actions; by contrast, cross-level, gauge, and vertical irregularities showed small amplitudes. The evolution power spectral density (EPSD) of the stochastic post-seismic residual track irregularities obeys a definite distribution in any frequency-space coordinate. A uniquely deterministic target post-seismic residual track irregularity can be constructed based on the stochastic irregularity set, and its safety guarantee rate can be precisely controlled by varying the significance level. Taking the first-order transverse natural vibration period as the x-axis and the amplitude of fitted post-seismic residual track irregularity as the y-axis, the response spectra of fitted post-seismic residual track irregularity can be created. The irregularity response spectra are applicable to stochastic structures.

Automated summary

This study focuses on the analysis of post-seismic residual track irregularity and post-seismic train speed threshold in earthquake-prone areas of the Chinese high-speed railway network construction. The research constructed a time-domain signal for post-seismic residual track irregularity based on the Gaussian pulse translation theory and established response spectra applicable to stochastic structures. The results show that residual alignment irregularity has a large amplitude under transverse seismic actions.