Experimental Research Progress of Seismic Metamaterials: Structural Configurations, Attenuation Mechanisms, and...

Seismic metamaterials (SMs) have emerged as a novel wave-control strategy for earthquake-resistant engineering, offering the potential to manipulate seismic waves via artificially designed periodic/resonant structures. Field and laboratory experiments are critical to bridge theoretical predictions and engineering practice, yet a systematic synthesis focusing on experimental progress remains lacking. This review systematically classifies SMs into buried (BSMs), above-surface (ASMs), and partially embedded (PESMs) configurations, summarizing their structural designs, attenuation mechanisms, experimental performance, and key limitations. Results show that SMs can achieve >70% attenuation in the 0-50 Hz seismic band, with buried periodic barriers reaching 99.7% energy blocking and forest-like ASMs achieving 93-99% Rayleigh wave reduction. PESMs exhibit superior adaptability to shallow soils, with bandgaps concentrated in 1.5-14.5 Hz (building-sensitive range). Current experiments have advanced from single mechanisms to multi-mechanism synergy and from specialized materials to conventional concrete/steel. However, critical gaps remain: scaling-induced deviations, poor complex-geology adaptability, lack of long-term durability, and insufficient multi-waveform control. Finally, we propose a 3-10-year engineering roadmap and outline future directions: multi-waveform regulation, soil-metamaterial dynamic matching, durability design, and full-scale intelligent upgrades. This work aims to provide a critical experimental reference for the practical deployment of SMs.