Effects of shear panel dampers on seismic response mitigation of high-speed railway simply supported bridge-track system under far-field and near-field ground motions

High-speed railway lines always have to cross the seismic zone with great earthquake risks leading to serious consequences. A replaceable steel panel damper (SPD) is proposed as an energy-dissipation device to mitigate the structural seismic responses. It is simulated as a simplified nonlinear spring embedded in structural system with the force–displacement behavior derived by plate-beam theory. To investigate the effect of SPD, a typical 5-span high-speed railway simply supported bridge-track system (HSRSBTS) validated by a shaking table test is established by ANSYS. A novel damage measure, the system relative damage ratio ( γ SRD ), is proposed to quantify the effect of SPD in the system and consider the potential component-level damage modes of both bending and shear. The structural system is investigated undergoing two ground motions suites in DBE- and MCE-level intensity, including both far-field and near-field records in transverse direction. The result indicates that a significant reduce (roughly 50%) of seismic response in rail and girder are contributed by SPD, while the system damage decreases about 10–15%, especially for near-field pulse-like ground motions with high intensity. The energy-dissipation capacity of SPDs with various configurations is examined to optimize the properties of SPD. It generally decreases with the increase in the elastic stiffness ratio r of the SPD to the fixed support, and the r = 2–2.5 are recommended in engineering practice. SPD is an effective and efficient device of structure to be adopted as an energy-dissipation component and the first defense line under far-field and near-field ground motions.