均匀降温下CRTSⅡ型高速铁路轨道板温度应力分析

Thermal Stress Analysis of CRTSⅡ Track-Slab of High-Speed Railway Under a Uniform Cooling Condition

根据无砟轨道板钢轨-轨道板-钢筋滑移线性本构关系,建立了均匀降温作用下纵连式轨道板温度应力计算模型.应用拉普拉斯变换方法求解平衡微分方程,得到钢筋和混凝土应力、位移的解析表达式,分析配筋率、扣件扣压力和板底摩擦力等参数对裂缝间距及轨道板内力、位移的影响.最后以京沪高铁CRTSⅡ无砟轨道板为例,计算30℃降温条件下的开裂间距,轨道板内力、位移随裂缝长度的分布规律.研究结果表明,解析表达式可以准确地分析轨道板的温度应力,为无砟轨道板设计提供理论依据.

A new calculation model of track-slab of high speed railway about temperature stress was established based on rail-track- slab-steel bar linear slip constitutive equations, and the analytic expression were derived using Laplace transform method. The influence of the parameters including reinforcement ratio,fastener buckle pressure and plate friction on the crack spacing and the changing characteristics of internal force and displacement of the track-slab under uniform cooling were studied with analytic expression. Finally,taking the CRTSII track plate under 301 cooling conditions with the respect to the Beijing-Shanghai high-speed railway as an example, the stress and displacement distribution of slab with the crack length and reinforcement ratio were calculated. I t can be concluded that temperature stress of CRTSII track-slab can be analyzed effectively using the method and provides theoretical basis of design for ballastless track structure.