高速铁路简支梁桥上轨道高低不平顺谱特征波长分析

Analysis on Characteristic Wavelength of Track Vertical Irregularity Spectral on Simply Supported Beam Bridge of High Speed Railway

以一客运专线为背景,采用周期图法计算桥梁段轨道高低不平顺功率谱密度,从频谱角度分析桥上轨道高低不平顺谱特征,利用动力学仿真与数值模拟探究轨道谱特征波长与下部结构的映射规律,分析周期性不平顺幅值对车辆动力响应的影响。结果表明:桥梁段轨道谱特征波长与桥梁、轨道板的结构有关;轨道高低不平顺谱中出现的特征波长由主要周期结构产生,波长符合1∶1/2∶…∶1/n的比例关系;次要周期结构在主要周期1/n处的分量有增益;轮重减载率、车体垂向加速度均与周期不平顺幅值正相关,轮重减载率在周期不平顺幅值达到6 mm时超出容许限值。

Taking a passenger dedicated railway as the background,the periodogram method was used to calculate the power spectral density of track vertical irregularity in the bridge section,analyze the track vertical irregularity spectral characteristics on the bridge from the perspective of spectrum,explore the mapping law between the track spectral characteristic wavelength and the substructure by using dynamic simulation and numerical simulation,and analyze the influence of periodic irregularity amplitude on vehicle dynamic response.The results show that the track spectral characteristic wavelength in bridge section is related to the structure of bridge and track plate.The characteristic wavelength in the track vertical irregularity spectrum is generated by the main periodic structure,and the wavelength conforms to the proportional relationship of 1∶1/2∶…∶1/n.The component of the secondary periodic structure at 1/n of the main period will have a certain gain.The wheel load reduction rate and the vertical acceleration of the vehicle body are positively correlated with the periodic irregularity amplitude.The wheel load reduction rate exceeds the allowable limit when the periodic irregularity amplitude reaches 6 mm.