Response spectra of fitted post‐seismic residual track irregularity for high‐speed railway
Jian Yu, Wangbao Zhou, Lizhong Jiang
Abstract
Abstract 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.