Full-Scale investigation on inclined ballastless cant track using concrete slab panel at high temperature setting

Abstract

The topography condition in the mountainous region has limited the construction of high-speed railways. Therefore, the proposed research aims to develop a new cant track model which is designed at a maximum inclination of 180 mm to simulate the curved sections on these highland areas. This construction methodology incorporates the advantages of the strong stress-bearing property of concrete slab panels and the robust stress distribution ability of the asphalt concrete trackbed. The installment of concrete slab and optimized asphalt concrete mixture were also used to counter the negative impact of the high temperature during summer in South Korea on the asphalt concrete layer. In this research, the performance of the cant track system was analyzed by using the Rail Load System built by the Korea Railroad Institute. There are two featured loading stages including the static load and cyclic load. The static load was designed in the loading and unloading process between 0 and 210kN with an amplitude of 30kN. Concerning the dynamic behavior on the testbed section, 3 million cyclic train loads were applied at a frequency of 7 Hz to simulate the train speed of 350 km/h. The thermal air blow system was installed surrounding the cant track to keep the temperature at the core asphalt concrete at a constant value. Overall, the full-scale testbed results confirm the positive applicability of the cant track since stress can be homogenously distributed along the track substructure. Moreover, the rail plastic displacement and tensile strain of asphalt concrete roadbed were noticeably reduced compared to the conventional long sleeper ballastless track.