We propose that wave propagation through a class of mechanical metamaterials
opens unprecedented avenues in seismic wave protection based on spectral
properties of auxetic-like metamaterials. The elastic parameters of these
metamaterials like the bulk and shear moduli, the mass density, and even the
Poisson ratio, can exhibit negative values in elastic stop bands. We show here
that the propagation of seismic waves with frequencies ranging from 1Hz to 40Hz
can be influenced by a decameter scale version of auxetic-like metamaterials
buried in the soil, with the combined effects of impedance mismatch, local
resonances and Bragg stop bands. More precisely, we numerically examine and
illustrate the markedly different behaviors between the propagation of seismic
waves through a homogeneous isotropic elastic medium (concrete) and an
auxetic-like metamaterial plate consisting of 64 cells (40mx40mx40m), utilized
here as a foundation of a building one would like to protect from seismic site
effects. This novel class of seismic metamaterials opens band gaps at
frequencies compatible with seismic waves when they are designed appropriately,
what makes them interesting candidates for seismic isolation structures.