A Study of Track and Train Dynamic Behavior of Transition Zone Between Concrete Slab Track and Ballasted Track

When a train is traveling along the transition such as slab and ballasted track, dynamic behaviors of rail system and train are abruptly changed. In R&D project, the newly-developed precast slab track system and track transition between slab and ballasted track was planned to construct in 2006 on the newly-built Jeolla-line. Maintenance demand, settlement and component degradation were predicted by a large dynamic response of rail transit system, so it was need to improve the performance the transition for the mitigation of the dynamic response of track. Some technical remedies, such as the use of gradual pad stiffness transition and auxiliary rail, were suggested, it was necessary to verify the design, before the commercial operation on the site. In this study, to estimate interface problems in the transition between slab and ballasted track, a dynamic interaction analysis technique was developed. The track and train coupled model was developed for the evaluation of dynamic behavior and the design of newly developed slab track transition on site. A procedure based on time history analysis was presented for solving problems concerning the dynamic interaction considering auxiliary rail and pad stiffness transition. After reinforcement of transition on site, the field tests have been carrying out under operating condition to evaluate the behavior of the transition zone and slab track.