Seismic risk transfer in multi-span simply supported beam bridges for high-speed railways

This study introduces an innovative method for seismic risk transfer in multi-span simply supported beam bridges used in high-speed railways. By integrating seismic risk transfer devices within bridge segments, the seismic risk is efficiently redirected to subgrade segments, thereby mitigating the seismic response of the bridge structure. Finite element models were created using OpenSees, and nonlinear time history analyses were performed with 40 sets of ground motion records to assess the impact of the seismic risk transfer system on both bridge and track structures. The study also examined the influence of the stiffness and yield displacement of the risk transfer devices on their effectiveness. Furthermore, a seismic response and damage assessment method based on hypothesis testing was proposed. This method was utilized to calculate and discuss the impact factors of the seismic risk transfer system for various pier heights and span numbers, and to evaluate its effect on the seismic damage risk of critical components. The findings demonstrate that the seismic risk transfer system can significantly reduce the variability in seismic responses across different spans, thereby enhancing overall seismic performance. The system transfers the seismic response of mid-span structures to side spans and subgrade segments, facilitating post-earthquake repairs and improving the overall economic efficiency of the bridge structure. This research provides new insights into the seismic design of high-speed railway multi-span simply supported beam bridges and holds significant implications for post-earthquake repair cost control.