Zeng Zhiping, Peng Guangzhao, Wang Weidong, Huang Xiangdong, Shen Shiwen, Shuaibu Abdulmumin Ahmed, Meng Xiaobai
School of Civil Engineering, Central South University, Changsha 410075, China.
Ministry of Education Key Laboratory of Engineering Structures of Heavy Haul Railway, Central South University, Changsha 410075, China.
Materials (Basel). 2022 Jan 20;15(3):770. doi: 10.3390/ma15030770.
The CRTS I type double-block ballastless track (CRTS I TDBBT) has the advantages of convenient construction and low cost, but it has low crack resistance and the temperature field distribution of the railway on the bridge is uneven and frequently changes, so it is necessary to study the mechanical properties of the CRTS I TDBBT under the load of a temperature field. The temperature field model of the CRTS I TDBBT on the bridge is established by finite element software, the real-time temperature field of the track bed slab is brought into the coupled model as a load, and the variation laws of the temperature stress of the CRTS I TDBBT under different schemes are compared. The temperature gradient in the CRTS I TDBBT track bed slab has the largest fluctuation range, and the positive and negative temperature gradient range can reach 93.34 °C. For the temperature longitudinal stress around the sleeper block of the track bed slab, the edge is the largest; the temperature longitudinal stress is reduced by at most 5.27% after the anti-cracking diagonal bars are added. When the expansion joint is added, the temperature stress can be reduced by up to 80.29%. The fluctuation range of the temperature gradient of the track bed is basically consistent with the fluctuation range of the local air temperature. The huge temperature difference leads to the occurrence of cracks in the track structure, and cracks are more likely to occur at the corners of the sleeper block. The addition of both anti-crack diagonal bars and expansion joints has an anti-crack effect, but the effect of adding expansion joints is better.
CRTS I型双块式无砟轨道（CRTS I TDBBT）具有施工方便、成本低的优点，但抗裂性较差，桥上铁路的温度场分布不均匀且变化频繁，因此有必要研究CRTS I TDBBT在温度场荷载作用下的力学性能。利用有限元软件建立桥上CRTS I TDBBT的温度场模型，将道床板的实时温度场作为荷载引入耦合模型，比较不同方案下CRTS I TDBBT温度应力的变化规律。CRTS I TDBBT道床板内温度梯度波动范围最大，正负温度梯度范围可达93.34℃。对于道床板枕下周围的温度纵向应力，边缘处最大；增设抗裂斜筋后，温度纵向应力最多降低5.27%。增设伸缩缝时，温度应力最多可降低80.29%。道床温度梯度的波动范围与当地气温波动范围基本一致。巨大的温差导致轨道结构出现裂缝，且裂缝更易出现在枕下拐角处。增设抗裂斜筋和伸缩缝均有抗裂效果，但增设伸缩缝效果更好。
