Seismic Response Control of High-Speed Railway Bridges with Prefabricated Multi-Layer Parallel-Connected Slit Steel Plate Shear Dampers

To mitigate and control the seismic damage risk of high-speed railway bridges and enhance their post-earthquake reparability, a prefabricated multi-layer parallel-connected slit steel plate shear damper is proposed by utilizing the energy absorption capacity of flexure–shear coupled deformation in dampers. A theoretical model for calculating the stiffness and load-bearing capacity of the proposed damper was established and validated through detailed finite element simulations. The results demonstrate that the damper exhibits stable energy dissipation efficiency under cyclic loading, along with a gradual reduction in post-yield stiffness. Subsequently, a numerical model of the high-speed railway track–bridge-damper systems (HSRTBDS) was developed, incorporating the contribution of the proposed damper to quantify its control over the seismic response of the HSRTBDS. The findings indicate that the damper effectively reduces the seismic responses of the girders, rail fasteners, and track slabs, with a maximum deformation reduction exceeding 30% in the supporting structures. However, the deformation and damage of the bridge piers slightly increased, though they remained within acceptable safety limits. The damper showed limited influence on the damage to rails, fasteners, and shear key slots. Overall, the effectiveness of the proposed damper in controlling the structural response of HSRTBD has been demonstrated and validated, providing insights for the seismic design of high-speed railway bridges in high-intensity seismic zones.