高铁常用跨度简支梁桥上轨道周期性不平顺影响分析

通过对桥梁徐变上拱设计和相应规定、轨道不平顺检测方法、实测资料以及线路规范的对比和理论计算,进行高铁常用跨度预应力混凝土简支梁桥上轨道产生波长为32 m的轻微周期性不平顺现象研究。结果表明:线路、桥梁规范中线路高低Ⅰ级管理值、梁跨竖向残余变形的规定是一致的;轨面不平顺静、动态检测结果不可以用来直接对比;京沪高铁桥上轨道周期不平顺的桥跨长度占比随着时间发展逐渐增大,开通4年后占比持平至约66%,桥上轨道周期性不平顺峰值均值、标准差及变异系数分别约为2.28 mm,0.57 mm和0.25;开通5年后98.4%,99.9%和100%的桥上轨道周期性高低不平顺峰值分别小于5,6和7 mm;当连续多跨简支梁徐变值均大于3 mm时,线路TQI高低已超过规范管理限值,建议通过轨面设置反预拱度,避免由梁体徐变带来的大面积轨道精调作业。

Effect of Periodic Track Irregularities on Simply Supported Beam Bridge with Common Span for High-Speed Railway

Based on the comparison and theoretical calculation of the design and the corresponding regulations of the bridge creep camber, the track irregularity detection method, the measured data and line specifications, the slight periodic irregularity with the wavelength of 32 m on the track of the prestressed concrete simply supported beam bridge with common span for high-speed railway was studied. Results show that the provisions of the high and low grade I management values of the line and bridge codes and the vertical residual deformation of the beam span are consistent. The static and dynamic detection results of rail surface irregularities can not be used for direct comparison. The bridge span length proportion of track periodic irregularities on the Beijing-Shanghai high-speed railway bridge increases gradually with the development of time, reaching about 66% from flat after 4 years of operation. The peak-to-peak mean value, standard deviation and variation coefficient of track periodic irregularities on the bridge are about 2. 28 mm, 0. 57 mm and 0. 25 respectively. After 5 years of operation,98. 4%, 99. 9% and 100% of the peak-to-peak values of track periodic irregularities on the bridge are less than 5 mm, 6 mm and 7 mm respectively. When the creep values of continuous multi-span simply supported beams are all greater than 3 mm, resulting in the TQI of the line exceeding the standard management limit. It is suggested to set the reverse pre-camber on the rail surface to avoid the large-area rail fine adjustment operation caused by the creep of beam body.