Shaking table test and numerical study of high-speed railway simply supported girder bridge with combined damping system subjected to strong earthquakes

Abstract

To reduce the damage of high-speed railway bridges in strong earthquake areas, this paper innovatively proposed a composite damping system consisting of “friction pendulum bearing (FPB) + metal dampers + limited-plates'. A scaled shaking table test and numerical simulations of a high-speed railway simply supported girder bridge under various earthquake intensities of 9° (frequently occurred earthquake (FOE), fortification earthquake (FE), and rarely occurred earthquake (ROE)) were performed to verify the feasibility and effectiveness of the composite damping system. The test results showed that in the case of FOE, the scaled bridge was intact; in the case of FE, the FPBs started sliding after the shear pins being cut off, and the metal dampers deformed accordingly, causing microcracks in the bottom of piers; in the case of ROE, the beam collide with the limited-plates, limiting the relative displacement of the pier and girder and extending the cracks on the base of the piers without concrete peeling. Then, a finite element model equipped with the composite damping system was calibrated by the test results. Furthermore, from the perspectives of seismic reduction rate and energy dissipation, it was further clarified that the combined damping system exhibited graded energy dissipation, seismic isolation, and displacement limitation functions, demonstrating superior seismic isolation performance. The research can offer a novel approach for the isolation technology of high-speed railway bridges in high intensity earthquake areas.