Experimental investigation on effects of track configurations on long-term behavior of ballasted track

The track settlement causes the deterioration of track geometry structure. Analysis of track settlement is a significant condition for determining the maintenance cycle. The long-term behavior of ballasted track may vary depending on the combination of the track configurations. In the present study, four ballasted tracks are studied through full-scale experiments to evaluate their respective performance in terms of track settlement. A load condition simulating a vehicle speed of 230 km/h is applied to the ballast tracks with a cyclic load of up to 1.5 million cycles. The long-term behavior prediction equations for the ballasted tracks used in Korea are presented in this study. The size of the sleeper and the thickness of ballast are analyzed to be the most influential track configurations for the long-term behavior of ballasted track. Results of the full-scale test showed that the effective area between ballast and subgrade is related to the long-term behavior of ballasted track. The track settlement decreases as the effective area between ballast and subgrade increases. Therefore, it is necessary to properly consider the effective area of the sleeper and the ballast thickness to inhibit the track settlement.