A novel metaconcrete barrier as backfill of foundation pit to mitigate ground-borne vibration

Low-frequency ambient vibrations induced by traffic have attracted widespread attention due to their adverse effects on nearby building structures and the residents. Traditional wave barriers, such as piles and trenches, require impractical large sizes to mitigate low-frequency vibrations. To address this problem, we propose a novel metaconcrete barrier as backfill of foundation pit. Specifically, a spring-mass system composed of lead and rubber is embedded in the backfill layer of foundation pit to attenuate low-frequency waves at subwavelength scale. The attenuation zones of the proposed metaconcrete barrier as backfill are investigated based on the periodic theory and the numerical model. Then this study is extended to the multi-resonance metaconcrete barrier and its vibration mitigation effectiveness is evaluated, accompanied by an analysis on the effect of its geometric parameters. The result demonstrates that the proposed metaconcrete barrier as backfill exhibits remarkable vibration reduction at subwavelength scale, which can overcome the shortage of traditional wave barriers in dealing with low-frequency vibration components. Also, the graded arrangement of multi-resonators can greatly expand its low-frequency attenuation range. This research offers a novel and practical vibration mitigation strategy in the field of civil engineering.