Effects of ballast renewal work at low temperature on inward rail displacements and axial rail forces of continuous welded rails on sharp curve

Abstract

This study aims to clarify the effects of the ballast renewal work at low temperature on the inward rail displacements and the axial rail forces of continuous welded rails on sharp curve. The authors measure the inward rail displacements and the changes in the axial rail forces caused by the ballast renewal works on the track having 400 m curvature radius and examine the effects of the work on the measurements. As a result, it becomes clear that the rail displacements occur by the two-day ballast renewal works with a total length of 16 m, even though the curve adjusting is performed after the works. The maximum value of rail displacement is 13 mm across the two-day works. The changes in the axial rail forces across the two-day works are -0.37 to 0.24 ℃ converted into the changes in the neutral temperature. The axial rail forces do not tend to be changed markedly in the compressive direction across the ballast renewal area due to the inward rail displacements. The changes in the neutral temperature due to the ballast renewal works are sufficiently smaller than the changes in that due to the rail creeps or the track maintenance which require the realignment of the axial rail forces or the reinforcement of the lateral ballast resistance.