A novel periodic in-filled metabarrier for mitigating train-induced vibrations

This study proposes a novel periodic in-filled metabarrier (PIMB) for mitigating train-induced vibrations. A number of periodic unit cells, consisting of a lead sphere and perforated rubber wraps, are embedded in soil to form the PIMB. The fundamental principle of this design lies in utilizing the localized resonance effect to induce subwavelength bandgaps, with resonant unit cells whose dimensions are considerably smaller than the incident wavelength. The performance of the PIMB in a homogeneous half-space is examined using three-dimensional finite element analysis. A parametric study is conducted to investigate the influence of barrier depth, barrier row numbers, and the rubber damping ratio. Laboratory specimen tests and physical model tests were conducted to evaluate the effectiveness of the PIMB unit cell and the engineered PIMB, respectively. The results indicate that the PIMB can achieve attenuation of up to 27 dB in the laboratory specimen test and up to 35 dB in the model box test. A time–history analysis, in which an actual train-induced vibration record was employed as the excitation input, was also conducted to further examine the vibration mitigation performance of the PIMB. Results from the experimental tests and numerical analysis confirm the potential of the PIMB in mitigating train-induced vibrations. • A novel periodic in-filled metabarrier (PIMB) is proposed to mitigate the train-induced vibrations. • A physical interpretation of the PIMB is presented. • A parametric study is conducted to investigate the influence of barrier depth, barrier row numbers, and the rubber damping ratio. • Laboratory specimen tests and physical model tests are conducted to evaluate the vibration mitigation performance of the PIMB.