2022/06/22 by Stéphane Brûlé, Brûlé, Stéphane, Bogdan Silviu Ungureanu +5
Earth and Planetary Sciences · Engineering · #Acoustic Wave Phenomena Research #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Geophysics (physics.geo-ph) #Geophysics and Sensor Technology #Materials Science (cond-mat.mtrl-sci) #Seismic Waves and Analysis
paper · pdf · doi:10.48550/arxiv.2206.10825
openalex publication_date 2022/06/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the dynamic surface response of neolithic stone settlements obtained with seismic ambient noise techniques near the city of Carnac in French Brittany. Surprisingly, we find that menhirs (neolithic human size standing alone granite stones) with an aspect ratio between 1 and 2 periodically arranged atop a thin layer of sandy soil laid on a granite bedrock, exhibit fundamental resonances in the range of 10 to 25 Hz. We propose an analogic Kelvin-Voigt viscoelastic model that explains the origin of such low frequency resonances. We further explore low frequency filtering effect with full wave finite element simulations. Our numerical results confirm the bending nature of fundamental resonances of the menhirs and further suggest additional resonances of rotational and longitudinal nature in the frequency range 25 to 50 Hz. Our study thus paves the way for large scale seismic metasurfaces consisting of granite stones periodically arranged atop a thin layer of regolith over a bedrock, for ground vibration mitigation in earthquake engineering.