高速铁路箱梁伸缩缝位移传感器研究

Study on Displacement Sensor for Expansion Joint of High-speed Railway Box Girder

高速铁路箱梁状态对轨道平顺性和行车安全具有决定性作用。由于箱梁滑移变化缓慢且微小,同时需克服电力牵引产生的强电磁干扰,实现自动化监测面临较大挑战。该问题的难点在于箱梁伸缩缝的起始缝宽不同,只有实现等精度测量,才能使不同箱梁伸缩缝的变化具备可比性。本文设计了一种光学低相干高速铁路箱梁伸缩缝位移传感器,在实验室条件下进行了抗振动性能测试,验证了传感器在常见低频振动工况下的性能,并在京津城际高速铁路简支箱梁伸缩缝的监测中应用。结果表明:受日照和温度的影响,箱梁伸缩缝上下表面的位移差异可达150μm,传感器的实测长期监测精度可达50μm。研究成果为实现高速铁路箱梁伸缩缝自动化监测提供了参考借鉴。

The condition of box girders in high-speed railways directly determines track smoothness and operational safety.Slow and minute variations in girder displacement pose challenges for monitoring,particularly in overcoming strong electromagnetic interference generated by electric traction systems and achieving automated monitoring.A key difficulty lies in the varying initial widths of expansion joints among different box girders,necessitating equal-precision measurement for comparative analysis of their changes.This study proposed an optical low-coherence expansion joint displacement sensor for high-speed railway box girders,which was subjected to vibration resistance testing under laboratory conditions.The sensor’s performance under common low-frequency vibration scenarios was verified,followed by its application in monitoring the expansion joints of simply-supported box girders on the Beijing-Tianjin Intercity High-speed Railway.Results show that,influenced by sunlight and temperature,the difference in displacement between the top and bottom surfaces of expansion joints can reach 150μm,with the sensor demonstrating a long-term monitoring accuracy of 50μm.These findings provide valuable reference for the implementation of automated monitoring of expansion joints in high-speed railway box girders.