Deformation characteristics and interfacial damage of CRTS II slab track joints under operating temperature conditions
Authors: DONG Bo, CHEN Zhi-yuan, ZHU Hao, CAI Xiao-pei, ZHANG Xing, HE Xu
Arching and cracking of joints between slabs have become a problem in China Railway Track System (CRTS) II slab track. The slab track is susceptible to complex temperature variations as a longitudinal continuous structure. Based on measured data, a thermal-mechanical coupling model of the track was established. The deformation characteristics and interfacial damage behavior of joints under typical temperature fields were studied. The findings indicate that the annual extreme temperature range of the slab track, fluctuates from −1.4 to 49.8 ℃. The annual temperature gradient within the vertical depth range of 0 to 0.2 m of the track varies between −16.19 ℃/m and 30.15 ℃/m. The vertical deformation of joints is significantly influenced by high temperatures, with a maximum measured deformation of 0.828 mm. The joint seams are primarily affected by low temperatures, which lead to a separation of 0.9 to 1.0 mm. Conversely, interlayer damage of joints is predominantly influenced by elevated temperatures. In summer, the maximum ratio of interface damage area in the joint can reach up to 95%, with the maximum debonding area ratio can be as high as 84%. The research results can provide help for joint damage regularity and deformation control of CRTS II slab track.
