Following each major earthquake that occurs close to nearby cities many people wonder what scientist and engineers can do to minimise the seismic hazard on society. Whilst scientist try to understand the mechanism of each fault system on the globe, engineers try to find solutions for buildings to be more safe.
One interesting experiment I came across lately is published in last month’s Physical Review Letters by Brûlé et al.,: Experiments on Seismic Metamaterials: Molding Surface Waves.
The authors show an experiment of a seismic test carried out using seismic waves generated by a monochromatic source. Measurements of the particles’ velocities show a modification of the seismic energy distribution in the presence of the metamaterial in agreement with numerical simulations using an approximate plate model. This large-scale experiment was needed to show the practical feasibility of seismic metamaterials for complex natural materials such as soils and to stress their importance for applications in civil engineering.
Top: The seismic testing device cross section in the x-z plane Middle: Photograph of the seismic metamaterial experiment. The 3 dashed perimeters account for the location of sensors, seismic metamaterial, and rotating source (a vibrating probe set on a crane). Bottom: Measurements for a monochromatic source. Experimental results map after interpolation between sensors: (a) the difference and (b) ratio of the measured energy field.
You can download the article here.
