双块式无砟轨道端梁区高温拱曲影响因素及控制技术

Influence Factors and Control Technology of High Temperature Arching in End Beam Area of Twin-block Slab Ballastless Track

针对高速铁路双块式无砟轨道线路路基段两头端梁区附近道床板上拱问题,采用有限元方法,研究不同温度组合、路基段长度及端梁桩土约束刚度对道床板上拱的影响规律。结果表明:道床板的温度变形是引起上拱的主因,但支承层的变形扰动及其与道床板的温度变形组合效应不可忽视;随着路基段长度的增加,上拱幅值增加趋势明显;端梁的桩土约束对上拱的影响较为复杂,在中间某一特定约束刚度时上拱达到峰值,而当约束刚度无论变大或变小,上拱都呈现变小的趋势;断开支承层对控制高温上拱变形效果不显著,断开道床板则效果显著,但需协调考虑对应区段的钢轨受力。

Aimming at the problem of the upward arching of the track slab near the end beam area on the two ends of the subgrade section of the line twin-block slab ballastless track of the high-speed railway,the finite element method was used to study the influence law of different temperature combinations,subgrade section lengths,and end beam pile-soil constraint stiffness.The results show that the temperature deformation of the track slab is the main cause of the upward arching,but the deformation disturbance of the support layer and its combined effect with the temperature deformation of the track slab cannot be ignored.As the length of the subgrade section increases,the amplitude of the upward arching increases significantly.The influence of pile-soil constraints on the upward arching of the end beam is relatively complex.The upward arching reaches its peak at a specific constraint stiffness in the middle space,meanwhile the constraint stiffness increases or decreases,the upward arching shows a decreasing trend.The effect of disconnecting the support layer on controlling the deformation of high-temperature upward arching is not significant.Breaking the track slab has a significant effect,but it is necessary to consider the rail forces in the corresponding sections.