Seismic Wave Damping System

Abstract

A seismic wave damping system, and a corresponding method, includes elements, embedded within a host medium, the elements defining a seismic damping structure, and the elements being arranged to form a border of a protection zone. The seismic damping structure is configured to attenuate power of a seismic wave, traveling from a distal medium to the host medium, that is incident at the protection zone. The seismic damping structure is characterized by a resonance frequency. The system further includes an anti-resonance damping structure positioned within the protection zone and configured to dampen a residual wave propagating within the protection zone at the resonance frequency. Embodiment systems offer synergistic advantages because resonance frequencies of seismic wave damping structures may be predicted by calculation and an anti-resonance damping structure may be built to attenuate waves of primarily only specific resonance frequencies supported by the seismic wave damping structure.

1 . A seismic wave damping system comprising:
 elements, embedded within a host medium, defining a seismic damping structure, the elements arranged to form a border of a protection zone, the seismic damping structure configured to attenuate power of a seismic wave, traveling from a distal medium to the host medium, that is incident at the protection zone, the seismic damping structure characterized by a resonance frequency; and   an anti-resonance damping structure positioned within the protection zone and configured to dampen a residual wave propagating within the protection zone at the resonance frequency.   
     
     
         2 . The seismic wave damping system of  claim 1 , wherein the resonance frequency is a function of a depth of the elements in the host medium and of a physical property of the host medium. 
     
     
         3 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure is configured to dampen the residual wave by being mechanically tuned to the resonance frequency. 
     
     
         4 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure is configured to dampen the residual wave by being mechanically tuned to a harmonic of the resonance frequency. 
     
     
         5 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure is configured to dampen the residual wave by being mechanically tuned to a subharmonic of the resonance frequency. 
     
     
         6 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure includes two or more anti-resonance damping structures configured to dampen the residual wave by being mechanically tuned to two or more respective frequencies selected from the group consisting of (i) the resonance frequency, (ii) harmonics of the resonance frequency, and (iii) subharmonics of the resonance frequency. 
     
     
         7 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure includes one or more Helmholtz resonators positioned on or within the host medium within the protection zone. 
     
     
         8 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure is an array of cylinders within the host medium within the protection zone. 
     
     
         9 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure is a seismic wave absorbing structure configured to dampen the residual wave by absorption. 
     
     
         10 . The seismic wave damping system of  claim 9 , wherein the seismic wave absorbing structure is a mass-in-mass lattice. 
     
     
         11 . The seismic wave damping system of  claim 1 , wherein the host medium is earth, and wherein the anti-resonance damping structure includes an array of trees planted in the earth within the protection zone and spaced periodically. 
     
     
         12 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure includes an array of scattering components positioned periodically. 
     
     
         13 . The seismic wave damping system of  claim 1 , wherein the anti-resonance damping structure includes one or more towers positioned on the host medium within the protection zone. 
     
     
         14 . The seismic wave damping system of  claim 13 , wherein the one or more towers are one or more flexible, steel-girded towers. 
     
     
         15 . The seismic wave damping system of  claim 13 , wherein the one or more towers have heights, extending vertically from a surface of the host medium, between a few meters and hundreds of meters. 
     
     
         16 . The seismic wave damping system of  claim 13 , wherein the one or more towers have heights, extending vertically from a surface of the host medium, of 100 m or less. 
     
     
         17 . The seismic wave damping system of  claim 13 , wherein each of the one or more towers has a cross-sectional dimension on the order of 1 m or on the order of 10 m. 
     
     
         18 . A method of constructing a seismic wave protection zone, the method comprising:
 embedding elements within a host medium, thus defining a seismic wave damping structure characterized by a resonance frequency and forming a border of a protection zone, wherein the seismic wave damping structure is configured to attenuate power of a seismic wave traveling from a distal medium to the host medium and incident at the protection zone; and   positioning an anti-resonance damping structure within the protection zone and configuring the anti-resonance damping structure to dampen a residual wave propagating within the protection zone at the resonance frequency.   
     
     
         19 . The method of  claim 18 , wherein configuring the anti-resonance damping structure to dampen the residual wave propagating within the protection zone at the resonance frequency includes configuring the anti-resonance damping structure based on one or more properties of the host medium and one or more properties of the elements. 
     
     
         20 . A method of seismic wave damping, the method comprising:
 converting an incident seismic wave propagating in a distal medium outside a protection zone into a residual seismic wave propagating within the protection zone at one or more resonant frequencies; and   dampening the residual wave within the protection zone via anti-resonance damping.