胀板区段的高低不平顺时频特征及其评估方法

Vertical irregularity’s time-frequency characteristics and evaluation method for slab-expanding section

高速铁路无砟轨道的胀板病害是轨道服役性能劣化的最主要表现之一。利用轨检数据,分析了高低不平顺的时域波形与频率分布特征,得到了胀板病害的6.45 m高低不平顺波长特征。基于小波理论,采用离散小波的Mallat算法提取6.45 m所在高低不平顺波长区间的样本特征数据。给出了胀板指数计算方法,建立了高速铁路无砟轨道胀板病害的检测方法。通过算例对文中所提算法的适用性和准确性进行验证。结果表明:由结构性胀板引起的高低不平顺具有明显的温度效应;利用该病害检测算法计算结果与现场病害资料对比,准确率达到80%以上,可有效地实现无砟轨道胀板病害的定位与检测,为我国高速铁路无砟轨道养护维修提供一定的技术支持。

Slab-expanding disease of ballast-less track of high-speed railway is one of main manifestations of deterioration of track service performance.Here,track detection data were used to analyze time-domain waveform and frequency distribution characteristics of track vertical irregularity and obtain 6.45 m vertical irregularity wavelength feature of slab-expanding disease.Based on the wavelet theory,Mallat algorithm of discretized wavelet was used to extract sample feature data within 6.45 m wavelength interval,then the calculation method for slab-expanding index was derived,and finally,the detection method for slab-expanding disease of ballast-less track of high-speed railway was established.The applicability and correctness of the proposed algorithm were verified with an example.The results showed that vertical irregularity caused by structural slab-expanding has obvious temperature effects;the calculation results obtained with the proposed algorithm are compared with actual detection data measured on site,the former’s accuracy rate reaches more than 80%;the proposed algorithm can be used to effectively realize positioning and detecting ballast-less track’s slab-expanding disease,and provide a certain technical support for maintenance and repair of China high-speed railway’s ballast-less track.