Abstract

A concrete track, such as Rheda 2000 is commonly used in high-speed railways in Korea, Germany, China, etc., to enhance the operational safety of trains and to reduce the maintenance costs. However, when settlement of embankment or a crack in the concrete slab track occurs, the durability of the concrete track deteriorates significantly. Transition zones are considered to be vulnerable and are often deformed in railway embankments. The characteristics of track support stiffness and stresses on the rail in a deformed section are different from those in an undeformed section. In this study, a field measurement and numerical analysis were carried out to identify the dynamic response on transition zones where the track is deformed. A numerical analysis model was built to simulate the deformed concrete slab track, and it was compared with measured data from field tests for verification. The field tests to measure the stresses on the rail were performed in a train speed range from 280 to 300 km/h. According to the numerical analysis, the dynamic characteristics of the track varied with train speeds, which were then compared with the allowable stresses of the concrete slab track.

Highlights

  • Concrete tracks, which increase the running stability of high-speed trains, compared with ballast tracks, are widely used in Korea, Germany, China, etc., with the development of high-speed railways.On the other hand, when settlement or cracking occurs in the concrete slab track, the durability of the concrete track deteriorates significantly, and the methods of repair of damaged track are very limited and difficult.A zone where a bridge and embankment or a tunnel and embankment join is called a transition zone

  • Kim analyzed principal stresses of the trackbed on a settled transition zone using a 3D finite element method (FEM), and the results showed that plastic behaviors of the trackbed are caused by shear deformation when the track irregularities and train speeds increase [1]

  • The results showed that the dynamic response of a two-part transition section is better than that of an inverted trapezoid transition section

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Summary

Introduction

Concrete tracks, which increase the running stability of high-speed trains, compared with ballast tracks, are widely used in Korea, Germany, China, etc., with the development of high-speed railways.On the other hand, when settlement or cracking occurs in the concrete slab track, the durability of the concrete track deteriorates significantly, and the methods of repair of damaged track are very limited and difficult.A zone where a bridge and embankment or a tunnel and embankment join is called a transition zone. Track support stiffness varies a lot in a short distance in the transition zone. Railway embankment settlement occurs more frequently in the transition zone. An impact load from the dynamic behavior of train operation is mostly generated from differential settlement on the trackbed. As the speed of the train increases, such as is the case on a high-speed line, wheel loads on track increase, due to the impact load in the section where differential settlement occurs in a short distance [1,2]. In. Infact, fact,aawheel wheelseldom seldomcomes comesunstuck unstuckfrom fromthe therail railwhile while becoming thetrain trainisisrunning; running;this thisisismore morelikely likelyto tooccur occurwhen whensleepers sleepersare arefloating, floating,railpads railpadsare arenot notaligned, aligned, the or track track irregularities not separated from the the rail rail in the zone zone of thisofpaper

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