A broadband seismic metamaterial with gradient resonators for earthquake-proofing reservoirs

Seismic fortification of reservoirs is crucial for ensuring the safety of both the reservoir structures and surrounding communities. Metamaterials offer an innovative approach to earthquake prevention and disaster mitigation by controlling or attenuating seismic waves in mountainous regions. In this paper, we present a local resonance-type gradient seismic metamaterial (LRGSM) to attenuate body waves and surface waves across a broad frequency range. The propagation performance of seismic waves through the finite LRGSM system is investigated by using the finite element method. The transmission spectrum and displacement fields of the LRGSM under compression and shear waves incidence are analyzed to validate its broadband attenuation capabilities from 9.03 Hz to 15.00 Hz. Notably, this design is extended to the half-space model, demonstrating the same attenuation effect of Rayleigh waves as observed for body waves. The findings confirm that the LRGSM effectively generates a same attenuation zone, thereby effectively protecting reservoirs.