Mapping the relationship between the temperature gradient of CRTS Ⅲ slab track on bridge and rail deformation in high-speed railways

Abstract

Temperature gradient is an important factor affecting the periodic rail deformation of CRTS Ⅲ and the running stability of high-speed trains. The Comprehensive Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method is employed for the analysis of test data in site from CRTS III slab tracks on high-speed railway bridges. The correctness of the coupling model has been validated through data on-site. To analyze the mapping relationship between the temperature gradient of the CRTS Ⅲ slab track on the bridge and rail deformation in high-speed railways, a rail-slab track-bridge thermal coupling model was established, and the rail deformation distribution characteristics of the slab track on the bridge under the complex temperature gradient load were calculated. Furthermore, a prediction model of rail deformation under the action of the complex temperature gradient was proposed. The study results showed that the intrinsic mode function (IMF) decomposed by the CEEMDAN method reflects the sensitive wavelength of track irregularity and quantitatively describes the corresponding relationship between amplitude and seasonal temperature. In the measured data, the maximum amplitude of rail deformation caused by temperature differences in different seasons was 1.99 mm, reflecting the significant impact of temperature gradient on the additional track irregularities on the bridge. Under the action of the temperature gradient, the rail deformation of CRTS Ⅲ slab track on the bridge is the superposition of periodic sinusoidal fluctuation of the track and parabolic fluctuation of the simply supported beam. This study could provide a new method for predicting rail deformation and controlling track smoothness, so as to improve the stability and operation efficiency of trains.