复合轨枕无砟轨道温度适应性分析

为研究温度荷载对复合轨枕无砟轨道影响,分别建立长枕埋入式和双块式复合轨枕无砟轨道有限元模型,分析两种轨道结构在整体降温和温度梯度下的离缝长度和轨距变化量,并给出降温限值。结果表明:在整体降温条件下,两种轨道结构均产生离缝,双块式轨道的轨距变化量随降温幅度变化较小,综合考虑离缝和轨距变化限值影响,长枕埋入式、双块式轨道降温幅度分别不应超过7,11℃;温度梯度下,两种轨道结构均不产生离缝,仅正温度梯度下长枕埋入式轨距变化量超过规范值。从复合轨枕轨道结构对温度适用性考虑,建议在较小温差地区如隧道内铺设双块式轨道,并注意浇筑时混凝土的温度。

Analysis of Temperature Adaptability of Composite Sleeper Ballastless Track

In order to find out the influence of temperature load on ballastless track of composite sleeper, finite element models for ballastless tracks with buried long sleeper and double-block composite sleeper are established respectively to analyze the seam length and gauge variation of the two tracks under the conditions of integrated cooling and temperature gradient, and cooling limits are defined. The results indicate that seams appear in both tracks under integrated cooling, and a slight change in the gauge variation occur in the double-block track under integrated cooling. In view of the integrated influence of the limit values of the seam and gauge variation, the temperature ranges of buried long sleeper and double-block tracks should not exceed 7 ℃ and 11 ℃ respectively; no seam appears in both tracks under temperature gradient, only the gauge variation of buried long sleeper track exceeds the standard value under positive temperature gradient. Considering the temperature applicability of the composite sleeper track, it is suggested that the double-block composite sleeper ballastless track should be laid in a relatively constant temperature zone, such as the tunnel, and attention should be paid to controlling the temperature in the process of concrete pouring.