Track Maintenance on the Korean High-Speed Line: The First Three Years of Experience

Abstract

The start of commercial operation of the Korean High Speed Train (KTX) in April 2004 required implementation of a systematic track maintenance program. As expected the KTX track maintenance team went through a major learning curve since its members previous track maintenance experience was based on conventional trains traveling at up to 140 km/h.

The KTX track between Seoul and Busan includes 148 bridges with a total length of 112 km. All bridges have ballasted track. The annual temperature variations cause longitudinal movement in the bridge deck expansion joints and loosening of the ballast and subsequent ballast and track settlement at the bridge deck expansion joints.

Other maintenance issues included flying ballast that caused some damage to sound barriers and falling of large pieces of frozen snow from the bogies onto the track at high speed caused in some instances to significant wheel and rail damage. Differential settlements of bridge abutments were observed which resulted from ground water flow under the abutment.

The noise in tunnels with concrete slab track was about 5 to 7 dB higher then in tunnel with ballasted track. The connection part at the articulated bogie frame was modified and the gap distance reduced in an effort to reduce and optimize the noise level of trains traveling through tunnels with concrete slab track. The KTX ridership is increasing year by year and the current KTX operating revenues exceed forecasts and are already, after 3 years, in the black.

The paper documents experiences of track maintenance for Korean High-Speed Rail, KTX, during the first three years, especially on bridge, ballast and slab, and noise issues. The KTX track between Seoul and Busan includes 148 bridges with a total length of 112 kilometers. All bridges have ballasted track. The annual temperature variations cause longitudinal movement in the bridge deck expansion joints and loosening of the ballast and subsequent ballast and track settlement at the bridge deck expansion joints. Other maintenance issues included flying ballast that caused some damage to sound barriers and falling of large pieces of frozen snow from bogies onto the track at high speed caused in some instances of significant wheel and rail damages. Differential settlements of bridge abutments were observed which resulted from ground water flow under the abutment. The noise in tunnels with concrete slab track was about 5 to 7 dB higher than in tunnel with ballasted track. The connection part at the articulated bogie frame was modified and the gap distance reduced in an effort to reduce and optimize the noise level of trains traveling through tunnels with concrete slab track.