Experimental Validation of a Small-Scale Metafoundation Using Shaking Table Tests

Buried mass-resonator systems, including metafoundations, have attracted increasing attention as an effective approach for mitigating vibrations induced by seismic waves in structural systems. In this study, a series of shaking table tests are conducted on a small-scale metafoundation to experimentally evaluate its vibration reduction performance under seismic excitation. The metafoundation model was fabricated using acrylic plastic and ethylene propylene diene monomer (EPDM) rubber foam, and its dynamic characteristics were examined through white noise and sine sweep tests. The attenuation zones identified from the experiments were validated through comparison with the frequency band gaps (FBGs) of the metamaterial obtained from numerical simulations. A simple small-scale structure was subsequently installed on the metafoundation, and the dynamic behavior of the combined system was investigated using white noise and sine sweep signals. The effectiveness of the metafoundation in reducing the seismic response of the structural system was further evaluated using earthquake ground motions. The experimental results demonstrate that the metafoundation significantly reduces the seismic response of the structural system at frequencies corresponding to the attenuation zone of the structural system with metamaterial.