A novel vibration barrier for low-frequency surface waves in the ground

As for certain engineering scenarios, such as open-air quarries and underground pipeline areas, vibration barriers are in urgent need. However, their design and construction face various challenges, especially for attenuating surface waves with low frequencies. Inspired by the topography of hills and periodic phononic crystal structures, a novel vibration barrier consisting of periodic soil strips is proposed. Firstly, utilizing the finite element method and the theory of periodic structures, the dispersion band diagram is calculated for the periodic soil strips. The corresponding band gap mechanisms are discussed by the displacement field of modes in the lower boundary of band gaps. Besides, a simplified model and a theoretical expression are proposed to analyze the minimum frequency of the band gaps. Through frequency domain analysis, the influence of the damping of soil strips on isolation effects is examined, and the dissipated energy is also quantified using a spatial Fast Fourier Transform. Finally, a comparison of the isolation effect between soil strip barriers and typical trench barriers is conducted. The results show that periodic soil strips can exhibit several band gaps, within which surface waves (SWs) can be effectively isolated. Soil strip barriers exhibit similar or even better vibration isolation effects compared to trench barriers, especially for isolating low-frequency vibrations. This study enhances our understanding of surface wave mitigation using periodic barriers and provides fresh insights for designing seismic metamaterials.