Railway subgrade settlement detection method via vehicle-vibration data

Abstract To address the current issue of a low detection efficiency for localized subgrade settlement deformation in high-speed railways, the adoption of inertial navigation equipment mounted on operating vehicles is proposed in this paper. Through the use of dynamic response data collected by the inertial navigation system during operation, corresponding subgrade settlement values are calculated. First, a subgrade settlement deformation transmission model is developed to analyze the mapping relationship between subgrade settlement and track surface geometric deformation. Second, on the basis of multibody dynamics and inertial navigation principles, a track surface deformation detection algorithm based on vehicle-mounted vibration data is proposed. This algorithm aims to integrate data from vehicle-mounted detection and ground-based monitoring systems. The effects of internal errors of the inertial navigation equipment, as well as external error factors such as the installation location, vehicle speed, and correction intervals for auxiliary information, on the detection accuracy are examined. Finally, the reliability and accuracy of the proposed computational method are verified through simulation experiments and field data. The field test results show that the maximum error at the settlement trough is only 2.88%, and the waveform-tracking performance is accurate. The results of this study can provide valuable technical support for subgrade settlement deformation detection in high-speed railways.