A New Seismic Isolation Method by Using a Periodic Foundation

Some investigations in the field of solid-state physics show that phononic crystal, one kind of periodic materials, can produce a band of frequency gap. When the frequency of a wave falls into the frequency gap, it cannot propagate in the phononic crystal. Enlightened by the concept of frequency gap, a new seismic isolation method by directly using a periodic foundation is studied based on the theory of elastodynamics in the present paper. The band gaps of two-component and three-component 2D period materials are obtained by using finite element method. The influences of the material and structural parameters on the band gaps are studied and a new kind of period foundation is designed. The dynamic responses of a frame structure with different foundations are studied. It is found that the new seismic isolation method can greatly reduce the seismic response than the traditional seismic isolation method, which means that a new seismic isolation technology has been found.