Abstract
Rail corrugations whose wavelengths are around 1.2m have been formed very heavily on slab track section, particularly in ascending slopes, in Shin-Kanmon channel tunnel of San-yo Shinkansen line. The rail corrugations are giving rise to noise and large interacting forces between wheel and rail which are one of main causes of not only track but also vehicle deteriorations. In this report, considering the findings obtained so far, plastic flow caused by longitudinal creepage on the rail surface was investigated with an optical microscopy and rust covering the rail surface was analyzed and identified with infrared rays absorbing spectra. From the investigated results, the mechanism of rail corrugations was studies focusing on driving forces of wheels to run up the relatively steep ascending slopes of channel tunnel, on wheel load variation excited at rail welds and on the decrease of traction coefficient caused by the rust covered on the running band of rail under the sea.
