埋地局域共振超屏障衰减地震表面波研究  

RESEARCH ON ATTENUATION OF SEISMIC SURFACE WAVES BY BURIED LOCAL RESONANCE METABARRIERS

作　　者：曾超 赵春风[1,2] 陈昌强 ZENG Chao;ZHAO Chun-feng;CHEN Chang-qiang(School of Civil Engineering,Hefei University of Technology,Hefei 230009,China;Key Laboratory of Earthquake and Engineering Vibration,China Earthquake Administration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]中国地震局工程力学研究所中国地震局地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《工程力学》2024年第10期1-11,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(52278302,51508148);中国地震局工程力学研究所基本科研业务费专项资助项目(2020EEEVL0404)。

摘　　要：局域共振超材料突破了Bragg散射型周期结构在低频应用的困境,实现结构的小尺寸控制大波长,因此该文提出将谐振器单元沿深度方向周期性布置形成埋地超屏障,并探究其对低频地震表面波的衰减性能。基于局域共振超材料的有效质量概念和有效介质方法,推导了全共振半空间和有限埋深超屏障中Rayleigh波的频散方程,并编制相应的计算程序求解得到理论频散关系。采用有限元分析软件COMSOL MULTIPHYSICS建立全共振半空间和有限埋深超屏障的二维单胞有限元模型,通过特征频率分析求解埋地超屏障的数值频散关系,验证理论简化分析方法的有效性,同时利用数值方法研究了超屏障埋深对频率带隙宽度的影响。建立有限埋地超屏障和Bragg散射型周期波屏障的传输分析模型,通过频域分析和瞬态分析方法研究了两种波屏障在谐波激励和地震动下的动力响应。研究表明:埋地超屏障具有带隙起始频率低、设计灵活的特点,对表面地震动具有明显的衰减效果,有望作为一种新型隔震技术应用于工程实践。Locally resonant metamaterials avoid the dilemma of Bragg scattering periodic structure applicated at low frequencies and achieve the manipulation of large-wavelength elastic waves with subwavelength size structure.Therefore,in this study,a buried metabarrier is proposed by periodically arranging the resonators along the depth direction,and its attenuation performance against low-frequency seismic surface waves is investigated.Based on the concept of the effective mass of locally resonant metamaterials and the effective medium method,the dispersion equations of Rayleigh waves in fully resonant half-space and finite buried metabarrier are derived,and the corresponding computational programs are programmed.2D unit cell finite element models of fully resonant half-space and finite buried metabarrier,developed in COMSOL MULTIPHYSICS,are designed to solve the numerical dispersion relation by characteristic frequency analysis and confirm the effectiveness of the theoretical analysis method.Simultaneously,the influence of buried metabarrier depth on frequency bandgap width is studied by numerical method.The transmission analysis model of finite buried metabarrier and Bragg scattering periodic wave barrier is established.The dynamic responses of the two barriers under harmonic excitation and ground motion are investigated by frequency domain analysis and transient analysis.The results show that the buried metabarrier has a lower initial frequency of bandgap and flexible design and has a significant suppression effect on surface ground motion,which is expected to be applied in engineering practice as a new seismic isolation technology.

关 键 词：埋地超屏障 局域共振 带隙特性 地震表面波 衰减性能 

分 类 号：TU435[建筑科学—岩土工程]