Engineered metabarrier as shield from seismic surface waves
نویسندگان
چکیده
Resonant metamaterials have been proposed to reflect or redirect elastic waves at different length scales, ranging from thermal vibrations to seismic excitation. However, for seismic excitation, where energy is mostly carried by surface waves, energy reflection and redirection might lead to harming surrounding regions. Here, we propose a seismic metabarrier able to convert seismic Rayleigh waves into shear bulk waves that propagate away from the soil surface. The metabarrier is realized by burying sub-wavelength resonant structures under the soil surface. Each resonant structure consists of a cylindrical mass suspended by elastomeric springs within a concrete case and can be tuned to the resonance frequency of interest. The design allows controlling seismic waves with wavelengths from 10-to-100 m with meter-sized resonant structures. We develop an analytical model based on effective medium theory able to capture the mode conversion mechanism. The model is used to guide the design of metabarriers for varying soil conditions and validated using finite-element simulations. We investigate the shielding performance of a metabarrier in a scaled experimental model and demonstrate that surface ground motion can be reduced up to 50% in frequency regions below 10 Hz, relevant for the protection of buildings and civil infrastructures.
منابع مشابه
Seismic velocity structure and depth-dependence of anisotropy in the Red Sea and Arabian shield from surface wave analysis
[1] We investigate the lithospheric and upper mantle shear wave velocity structure and the depth-dependence of anisotropy along the Red Sea and beneath the Arabian Peninsula using receiver function constraints and phase velocities of surface waves traversing two transects of stations from the Saudi Arabian National Digital Seismic Network. Frequency-dependent phase delays of fundamental-mode Lo...
متن کاملExperiments on seismic metamaterials: molding surface waves.
Materials engineered at the micro- and nanometer scales have had a tremendous and lasting impact in photonics and phononics. At much larger scales, natural soils civil engineered at decimeter to meter scales may interact with seismic waves when the global properties of the medium are modified, or alternatively thanks to a seismic metamaterial constituted of a mesh of vertical empty inclusions b...
متن کاملAn Efficient Algorithm for General 3D-Seismic Body Waves (SSP and VSP Applications)
Abstract The ray series method may be generalized using a ray centered coordinate system for general 3D-heterogeneous media. This method is useful for Amplitude Versus Offset (AVO) seismic modeling, seismic analysis, interpretational purposes, and comparison with seismic field observations.For each central ray (constant ray parameter), the kinematic (the eikonal) and dynamic ray tracing system ...
متن کاملJointed Rock Mass Effects on the Seismic Waves Scattering from the Canyon Sites in the Dam's Support
Seismic study of canyon sites has always been one of the important fields of seismic studies because of massive structures such as dams that are built in such sites. Jointed rock mass in rock canyon sites is one of the main site effects that can change the seismic waves. In this research, we studied the influence of this factor on the scattering of seismic waves. To fulfil this goal, we employe...
متن کامل