Periodic foundation piles for the seismic protection of structures

Abstract

In recent years the applications of metamaterials for building protection have garnered considerable attention. In this study a new device for the seismic protection of new and existing structures based on resonant metamaterials has been presented. This device, called Periodic Foundation Piles, applies to deformable soil deposits in order to filter shear waves in a specific frequency range and consists of an array of vertical periodic and relatively small resonators, suitably tuned to one or more natural frequencies of the soil deposit. The performance of this system in reducing the amplitude of a seismic motion has been shown by using a non-linear one-dimensional shear beam model subjected to real acceleration records at the base. A soil deposit with increasing shear wave velocity profile has been considered; the nonlinear behavior of the soil has been modeled through the Iwan model which has been calibrated using a normalized secant shear modulus curve. Numerical results are shown in terms of peak ground acceleration, horizontal displacements and shear strain profiles, as well as in terms of Fourier amplitude and response spectra. The results of the analysis indicate that periodic foundation piles may provide efficient seismic protection for both new and existing structures.