基于疲劳寿命理论的无砟轨道脱空等级划分

采用有限元软件ANSYS建立CRTSⅢ型板式无砟轨道模型,研究脱空形式和脱空程度对无砟轨道疲劳寿命的影响。采用混凝土弯拉疲劳方程计算无砟轨道疲劳寿命,计算时不考虑预应力和温度梯度仅考虑列车荷载的影响。计算结果表明,随着脱空程度增大,4种脱空形式均会显著降低无砟轨道疲劳寿命,且板端脱空的影响最大。据此提出了脱空等级划分原则,并依据无砟轨道疲劳寿命影响系数将无砟轨道脱空划分为轻度脱空、中度脱空和重度脱空3个等级。建议参照离缝的修补方法确定各脱空等级相应的修补材料和工艺。

Void Grade Classification of Ballastless Track Based on Fatigue Life Theory

The model of CRTSⅢslab ballastless track was established by using the finite element software ANSYS to study the influence of void form and void degree on the fatigue life of ballastless track.The fatigue life of ballastless track was calculated by bending tension fatigue equation of concrete when the influence of prestress and temperature gradient on fatigue life was not considered,and only the train load was considered.The calculation results show that with the increase of void degree,the fatigue life of ballastless track will be significantly reduced by four kinds of void forms,and the effect of slab end void is the greatest.Based on these results,the principle of void grade classification was put forward,and the void of ballastless track was divided into such three grades as light void,medium void and heavy void according to the influence coefficient of ballastless track fatigue life.It is suggested to determine the corresponding repair materials and processes for each void grade by referring to the repair method of the gap.