铁路无缝线路极限状态法和容许应力法设计对比研究

Comparison Studies of Limit State Method and Allowable Stress Method for Railway Continuous Welded Rail

为研究Q/CR 9130—2018《铁路轨道设计规范(极限状态法)》对无缝线路设计的影响,从不同等级的多个铁路项目中选取多座桥梁,对比分析极限状态法和容许应力法的无缝线路设计结果。结果表明:(1)极限状态法计算的最大温降普遍比容许应力法温降限值大,最多大2.0℃,增幅最大为3.0%;极限状态法计算的最大温升普遍比容许应力法温升限值小,最多小1℃,降幅最大为1.5%;二者断缝检算无差别;(2)建议特殊工况采用极限状态法进行无缝线路设计时,同时采用容许应力法校核。

The influence of the limit state method in the Code for Railway Track Design(the limit state method)(Q/CR 9130-2018)on the design of CWR is studied in this paper.Several bridges are selected from railway projects of different grades,and the design results of CWR by limit state method and allowable stress method are compared and analyzed.The results show that:(1)The maximum temperature drop calculated by limit state method is generally larger than that calculated by allowable stress method.The maximum temperature drop is increased by 2.0℃and the maximum increase is 3.0%.The maximum temperature rise calculated by the limit state method is generally smaller than that calculated by the allowable stress method.The maximum temperature rise is reduced by 1℃and the maximum reduction is 1.5%.There is no difference between the two methods in fracture checking.(2)And it is suggested that the limit state method should be used in the design of CWR under special working conditions,and the allowable stress method should be used for checking.