Shaking table test of vertical isolation performances of super high-rise structure under metro train-induced vibration

Abstract

Metro systems are integral to improving transportation efficiency and providing convenience to the public; however, they cause environmental vibrations. To analyze the metro vibration propagation law and vibration isolation performance of a 120 m super high-rise structure positioned directly above two metro tunnels, a shaking table test at a 1/30 scale ratio is conducted in this study. First, a model for the shaking table test is designed and manufactured, and measurements of metro train-induced ground vibrations obtained on site are input into the model. Subsequently, vertical vibration tests are performed on the models with and without laminated rubber isolation bearings. Finally, their dynamic characteristics, vibration propagation law, and vibration isolation effect are analyzed, and the vertical vibration isolation mechanism of the structure is discussed. The results indicate that the metro vibration exerts a resonance effect on non-isolated super high-rise structures, thus resulting in the progressive amplification of the metro vibration response along the floors of the structure. The vibration isolation layer formed by the laminated rubber isolation bearings significantly reduces the vertical modal frequency and increases the vertical damping ratio of the super high-rise structure, thus effectively attenuating the vertical metro vibration. Unlike the non-isolated structure, the vibration-isolated structure can avoid severe structural resonance responses in the dominant frequency band of the metro vibration. This study aims to offer insightful considerations for evaluating metro vibrations in super high-rise structures and may serve as essential reference for vertical vibration isolation.