Study on the characteristics of rail corrugation for Chongqing subway line with large slope

Rail corrugation is among the most difficult problems in rail irregularity control of Chongqing subway which is special for its large longitudinal slope. In this study, the length of rail corrugation along the line was investigated and analyzed, the result shows the rail corrugation is closely related to the line slope and curve radius, it increases with the decrease of curve radius, meanwhile, when the line slope exceeds 30%, the occurrence of rail corrugation increases dramatically. The difference of rail corrugation at inner and outer rail of curve section also be tested, the result indicates that length and amplitude on the inner rail are larger than that of the outer rail at curve region. In addition, the rail corrugation at horizontal and vertical composite section is more serious, lead to higher vibration and noise to the wheel-rail system of subway.