季冻区CRTS I型无砟轨道不平顺规律及受力特性

Irregularity properties and stress characteristics of CRTS I ballastless track in seasonal frozen area

摘要:

为探讨路基冻胀变形对轨道不平顺及结构受力的影响规律,基于ANSYS有限单元分析方法,以哈大高速铁路冻胀区路基段为研究基础,建立了考虑限位凸台、凝胶树脂及层间粘结接触特征的CRTS I型板式无砟轨道-路基冻胀冻融耦合精细化有限元模型. 在此基础上,探讨局部冻胀区路基冻胀变形发生位置、不同冻胀波长及幅值对无砟轨道结构的影响,分析了短波冻胀下轨道不平顺、层间离缝特性与静力学性能. 结果表明:短波冻胀时无砟轨道结构不平顺范围、变形、离缝、受力等各项指标均随冻胀波长的减小、冻胀峰值的增加而增大；冻胀发生于底座板板中时对轨道结构受力影响最大,冻胀发生于底座板伸缩缝时对轨道结构变形离缝影响最大；相对于轨道板结构,底座板承受拉应力最大,冻胀发生于底座板板中时结构受力影响更大；在轨道结构抗拉强度方面,底座板为限制结构,建议冻胀检修限值的波长为10 m、峰值为5 mm.

Abstract:

To investigate the influence of subgrade frost heaving deformation on track irregularity and structural stress, based on the ANSYS finite element analysis method and the research on the subgrade section of the frost heaving zone of the Harbin-Dalian high-speed railway, the spatial refinement finite element model of CRTS I type ballastless track was established by considering the characteristics of limit boss, gel resin, and interlayer contact. On this basis, effects of the locations of frost heaving deformation and different frost heaving wavelengths and amplitudes on the ballastless track structure were discussed, and the track irregularity, interface crack characteristics, and static performance were analyzed. Results show that under short-wave frost heave, indicators of irregularity, deformation, interface crack, and stress of the ballastless track structure increased with the decrease of the frost heaving wavelength and the increase of the frost heaving amplitude. When the frost heave occurred in the center of the baseplate, the stress on the track structure was the most affected, and when the frost heave occurred in the baseplate expansion joint, it had the greatest effect on the deformation and interface crack of the structure. Compared with the track slab, the baseplate bore the largest tensile stress, and the structural stress was more affected when the frost heave occurred in the center of the baseplate. In terms of the tensile strength of the ballastless track, the baseplate was the limited structure, and the frost heaving limiting values ware recommended to be 10 m for wavelength and 5 mm for amplitude.