Metamaterial design principles for mitigating low-frequency traffic-induced soil vibrations

Abstract

As urbanization intensifies and rail and road traffic increase, infrastructure and buildings face growing challenges from ground-borne vibrations, particularly at low frequencies. Traditional mitigation methods, such as heavy masses or stiff trenches, are often ineffective due to the large wavelengths involved. This research investigates metamaterials—mass–spring systems with viscous damping—as a novel solution capable of attenuating low-frequency vibrations through local resonance. Three metawedge configurations—uniform, wave conversion, and rainbow trapping—were evaluated at a target frequency of 10 Hz, typical of soil vibrations induced by trains and traffic. The wave conversion metawedge proved most effective at mitigating surface vibrations, while the rainbow trapping metawedge minimized impact on the surrounding environment by dissipating rather than redirecting energy. Based on these findings, design criteria were developed, including the relative resonator bandwidth (RRBN), optimal mass range, and resonator spacing considerations. Additionally, the potential of impact-based resonators to enhance energy dissipation by exciting higher frequencies was explored. While promising results were observed in a simplified two-degree-of-freedom system, numerical simulations on a soil domain revealed unexpected amplification, highlighting the need for further investigation. This work establishes a foundation for the practical design of metawedges and identifies directions for future research into nonlinear and impact-based vibration mitigation strategies.