Evolutionary power spectrum density of earthquake-induced rail geometric irregularities

Abstract

China’s high-speed railway (HSR) construction has gradually extended to earthquake-vulnerable areas in recent years. However, there is currently a lack of studies on the characteristics of earthquake-induced rail irregularities, making it impossible to ascertain the threshold of post-earthquake train running speed. Taking the multi-span HSR simply supported girder bridge of a CRTS II-type track system as the research focus, the distribution models for residual rail irregularity under random seismic actions have been analyzed in this study. The statistical distribution of the evolutionary power spectrum density (EPSD) of the residual rail irregularity set is also explored. Based on the obtained results, the EPSD of earthquake-induced rail geometric irregularity was calculated, and a time-domain sample for earthquake-induced rail geometric irregularity was developed. Finally, the equating method of earthquake-induced rail geometric irregularity under different span numbers was discussed, and a method for fitting earthquake-induced rail geometric irregularity was proposed.