Experimental Study on the Seismic Mitigation Performance of Metafoundations on a Uniform Soil Layer

The seismic mitigation performance of a metafoundation with soil-structure interaction was investigated utilizing shaking table tests. The results indicated that the metafoundation's performance strongly depended on the coupling among the frequencies of the soil layer, structural systems, and input motions. Due to resonant effects, the response of the controlled structure could be greater than that of the uncontrolled superstructure at small input PGAs. By contrast, the metafoundation exhibited excellent mitigation effects at large PGAs. A simplified elastic model was validated by the experimental results. Then the validated model contributed to the interpretation of experimental phenomena based on equivalent linear parameters.