Unsupervised Stiffness Evaluation of High-Speed Railway Bridges Using Periodic Monitoring Data

The operational performance of high-speed railway bridges is controlled by stiffness, and the reduction in bridge stiffness leads to a decline in ride comfort. Therefore, it is very important to periodically evaluate the stiffness of high-speed railway bridges. To reasonably evaluate bridge stiffness without operation interference, a high-speed railway bridge stiffness evaluation method is proposed in this paper based on regularly solving the deflection limit and the most unfavorable deflection based on monitoring data. First, the analytical solution of the deflection limit of any bridge that meets the comfort requirements is derived by using the real displacement of the train wheelset. Then, the virtual calculation method of the most unfavorable deflection of the bridge based on the influence line is proposed. The bridge stiffness evaluation is achieved by comparing their periodical calculation results. Finally, the proposed method is verified by the long-term monitoring data of a long-span high-speed railway bridge. The results show that the proposed method can automatically calculate the time-varying curve of the bridge deflection limit and the most unfavorable deflection. Moreover, the evaluation results are intuitive and effective and show the time-varying trend analysis of bridge stiffness. The research results provide a simple and feasible method for the unsupervised stiffness evaluation of high-speed railway bridges.