Assessing running safety of high-speed trains on long-span cable-stayed bridges based on in-situ monitoring data

This paper presents a new method for assessing the running safety of high-speed trains passing through long-span cable-stayed bridges based on in-situ monitoring data. The monitoring data include the girder vertical deflection and girder-end rotation of bridges. Vertical deformation is utilized to derive the vertical acceleration formula of high-speed trains, and girder-end rotation is utilized to judge the arrival time of the train. According to the specified vertical acceleration limit of the train, the vertical deflection threshold of the bridge is derived from the vertical acceleration formula. The first derivative of the sinusoidal half-wave function of the side-span is utilized to obtain the girder-end rotation threshold, and the safety threshold system is established. The bridge deformation safety threshold system is then used to assess the running safety of the bridge. To verify the presented method, the bridge deformation thresholds calculated using the proposed method are compared with finite element analysis results. The proposed method avoids complex train-bridge coupling numerical simulation in acquiring the dynamic response of high-speed trains, largely improving computation efficiency and enabling real-time assessment of train safety.