Comparative analysis of metro-induced vertical vibrations in inter-story isolated, base isolated, and fixed base structures through shaking table tests

Vibrations induced by the metro, have a significant impact on human comfort and essential equipment in structures adjacent to or built on a metro. To investigate and compare the metro-induced vibrations of the inter-story isolated structure (IIS), base-isolated structure (BIS), and fixed-base structure (FBS), this study conducted 1/10-scaled shaking table tests on the three structures under four different measured metro-induced vertical ground vibrations. The maximum acceleration amplification coefficient (AAC) and acceleration frequency spectra were quantitatively analyzed, and the distribution of vertical acceleration response at different points on the slab and along the height of the building were compared. These results indicate that isolation can reduce the vertical vibrations of the slab. The acceleration at the center of the slab was 30% higher than that at the corners of the slab in the FBS, whereas the accelerations at the center and corners of the slab in the BIS and IIS were approximately identical, the difference of accelerations was less than 8%. The AACs of the FBS generally increased along the height of the building, the average value of AACs associated with peak acceleration ranged from 4.5 to 5.1. Notably, AACs of the BIS and IIS were approximately uniformly distributed along the height of the building, the average value of ACCs associated with peak acceleration ranged from 1.4 to 2.0.