高铁桥上有砟轨道梁端周期不平顺演变规律及道床支承状态检测方法

Evolution Law of Periodical Irregularity at Beam End and Roadbed Supporting State Detection Method of Ballasted Track on High-Speed Railway Bridge

针对高速铁路简支梁桥上有砟轨道梁端周期不平顺的形成机理及演变规律开展研究,重点分析环境温度对轨道周期不平顺的影响规律,并提出一种能快速检测有砟轨道枕下道床支承状态的方法(BDS法)。结果表明:环境温度荷载引起的梁端道砟滑移流变会导致梁端道床支承刚度不足,引起轨枕局部空吊,导致梁端轨道高低周期不平顺,且环境温度变化量越大,梁端轨道高低不平顺变化量越大;32 m简支梁有砟轨道梁端周期不平顺会引起脱轨系数最大值增加25.4%,平均值增大11.9%,轮重减载率最大值增大178.68%,平均值增大130.27%。BDS法可实现枕下道床支承状态的快速无损检测,可与小型捣固机配合对高铁有砟轨道梁端周期不平顺进行整治。

Aiming at the formation mechanism and the evolution laws of the periodical irregularity at the beam end of ballasted track on the simply-supported beam bridge of high-speed railway,the influence of ambient temperature on the orbital period irregularity was mainly analyzed;and a method(BDS method)that can quickly detect the supporting state of the ballast bed under the sleeper was proposed.The results show that the sliding and rheological behavior of the beam-end ballast due to the ambient temperature can cause insufficient supporting stiffness of the ballast bed at the beam end,leading to partial suspension the sleepers,and resulting in periodically longitudinal irregularity of the beam-end track.The larger the ambient temperature change,the greater the variation of the longitudinal irregularity of the beam-end track.The irregularity of the ballasted track at the end of the 32 m simply-supported beam will result in an increase of 25.4%in the maximum derailment coefficient and 11.9%in its average,as well as an increase of 178.68%in the maximum wheel load reduction rate and 130.27%in its average.The BDS method enables fast and non-destructive testing of the ballast bed supporting state under the sleeper,and can be used in conjunction with small tamping machines to rectify the periodic irregularity in the ballasted track at the beam end of high-speed railways.