路基冻胀对CRTSⅢ型板式无砟轨道受力和变形的影响研究

Influence of Subgrade Frost Heaving on the Deformation and Stress of CRTS Ⅲ Slab Ballastless Track

为研究严寒地区高速铁路路基冻胀对CRTSⅢ型板式无砟轨道的影响,建立CRTSⅢ型板式无砟轨道-路基空间耦合有限元模型,分析路基冻胀位置、冻胀波长和幅值对CRTSⅢ型板式无砟轨道受力和变形的影响。结果表明:路基冻胀作用位置对轨道结构的受力和变形影响较大,路基冻胀发生在底座板板中时层间离缝和轨道受力最大;轨道结构各层的位移、层间离缝和受力均随路基冻胀幅值的增大而增大,随路基冻胀波长的增大而减小;路基冻胀幅值限值随路基冻胀波长的增大而增大;综合考虑底座板与路基基床表层的层间离缝和底座板混凝土允许拉应力限值,当路基冻胀波长为20 m时,建议冻胀幅值应小于10 mm。

In order to study the influence of subgrade frost heaving on the stress and deformation of CRTSⅢslab ballastless track in severe cold area,a spatial coupling finite element model for CRTSIII ballastless track is established.The stress and deformation of CRTSIII ballastless track are analyzed with different frost heaving wavelength and amplitude.The results show that the frost heaving position has a great influence on the deformation and stress of track structure.The layer gap and stress of track structure are the most unfavorable when the subgrade frost heaving is acting on the bottom of concrete roadbed.The deformation,layer gap and tensile stress of track structure increase with the increase of the subgrade frost heaving amplitude and decrease with the increase of subgrade frost heaving wavelength.The limit value of subgrade frost heave amplitude increases with the increase of frost heave wavelength.Considering the limit value of gap between concrete roadbed and subgrade and tensile stress of concrete roadbed,the frost heaving amplitude should be less than 10 mm when the frost heaving wavelength of subgrade is 20 m,.