Design principles of seismic metasurfaces to control love waves

Metasurfaces, consisting in an array of resonant inclusions or resonant elements placed at a waveguide free surface, can be designed to interact with elastic waves and used to redirect, steer or absorb the elastic wave energy. Metasurfaces in half spaces are capable to support the propagation of shear horizontally polarized waves and to open band gaps in the spectrum of vertically polarized Rayleigh waves. In this work, we discuss the possibility of designing a metasurface to achieve control of seismic Love waves. We analytically derive the dispersion law of Love waves existing below a resonant metasurface and observe how surface resonators can significantly modify the mode shapes and phase velocity of Love waves. Love waves can be controlled at the seismic scale by designing a metabarrier of meter-scale resonators using steel masses restrained by elastic connectors. We guide the design of such metabarrier using the derived analytical dispersion relation and show its ability to manipulate Love waves in the frequency range relevant for seismic isolation.