Temperature field and thermal effects of the longitudinal connected slab track based on the measurement data and thermal-fluid-structure coupling analysis

Abstract

The temperature field and thermal effects are important factors affecting the serviceability of the longitudinal connected slab track and the safety of high-speed trains, which are necessary to deeply understand. To analyze the temperature field and thermal deformation of the longitudinal connected slab track, based on the heat transfer processes between the track and the environment, a three-dimensional thermal-fluid–structure coupling analysis model is established. The meteorological factors are comprehensively considered in the model, and the temperature field and the thermal effects of the longitudinal connected slab track can be thoroughly investigated. Good agreement is observed between the calculated temperatures of the model and the measured temperatures at the testing platform. On this basis, the temperature and deformation of the longitudinal connected slab track in typical dates in Beijing are analyzed. The results indicate that the maximum temperatures of the track and the time of their occurrence vary in different seasons. The positive temperature gradient is greater than the negative temperature gradient. The temperature distribution of the slab track shows significant non-uniformity in the transverse direction along the track. In summer, the slab track has a U-shaped temperature distribution in daylight, while in winter, the slab track has an S-shaped temperature distribution. The uneven distribution of the track temperature causes uneven deformation of the precast slab. The arching deformation of the precast slab is greatest in summer. Focused observation of the precast slab during the hot season is required to prevent excessive deformation and instability of the slab. The construction temperature of the slab track has pronounced effects on track deformations. The construction temperature should be strictly controlled to prevent the track cracking or instability.