周期性排桩和波屏障在土木工程减振中的应用研究

发布时间：2018-03-14 10:32

本文选题：周期性排桩　切入点：周期分形排桩　出处：《北京交通大学》2014年博士论文　论文类型：学位论文

【摘要】：摘要：本文从固体物理学的周期性理论出发,研究了土木工程中的周期性排桩(如周期性实心／空心排桩、周期性填充排桩和周期性分形排桩)和周期性波屏障结构。周期结构具有独特的衰减域禁波特性,当弹性波的频率落在衰减域内时,弹性波不能在周期介质中传播。另外,即使弹性波的频率在衰减域外,经过特殊设计的周期结构对弹性波的传播具有方向特性,即波的能量只能沿着某些方向传递,而在其他方向产生振动盲区。利用衰减域的禁波特性和波动传播的方向特性,就可以设计出具有减振、隔振功能的周期结构。这些周期结构可以应用到土木工程中的环境减振以及地震动的隔离当中。本文的研究目的是通过对这类周期结构的系统研究,为土木工程减振(震)方法提出新思路。本文通过理论研究、数值模拟以及对比其他研究者的试验结果的研究方法,首先利用级数展开技术和有限元法,求解了不同形式周期结构的频散曲线。然后,利用有限元技术,建立合理的分析模型和边界条件,进而分析了各种二维、三维周期结构的散射波场。通过和其他作者的实验结果对比,说明了理论结果的正确性和衰减域的存在性。本文的创新性成果主要有： (1)提出利用固体物理学中的周期性理论分析排桩的桩-土相互作用,用衰减域的概念解释周期性排桩对弹性波的频散特性；提出利用周期性排桩的衰减域特性实现对环境振动的衰减。 (2)获得了周期实心排桩和周期空心排桩的衰减域,并对衰减域的影响因素进行了系统研究；揭示了土的弹性模量、桩的半径和周期常数对周期性排桩衰减域的重要影响,得出常见尺寸的排桩易于隔离中频振动的结论。 (3)研究了周期填充排桩的面内和面外衰减域,并对衰减域的影响因素进行了分析；利用局域共振机理和布拉格散射机理对周期填充排桩衰减域的合理性进行了解释,将局域共振型周期填充排桩拓展用于低频减振。 (4)对周期分形排桩的衰减域和方向传播特性,进行了理论研究和数值模拟,揭示了代数和填充率对周期分形排桩衰减域的影响规律。 (5)设计了具备三维隔振(震)能力的周期性波屏障,为环境减振以及地震动隔离提出新思路。通过本文研究,不仅可以深入了解周期结构对弹性波的散射机制和减振效果,而且对揭示周期性排桩的桩-土相互作用机理、弹性波在桩-土之间的能量转换和耗散机理、建立周期性排桩在人工振动下的理论分析模型与设计方法、以及新型波屏障的设计,均具有非常重要的指导意义。
[Abstract]:Abstract: This article from the periodicity theory of solid state physics, studies the periodicity in civil engineering piles (such as periodic solid / hollow piles, with periodic pile rows and periodic fractal piles) and periodic wave barrier structure. Periodic structure has no unique characteristics of the wave attenuation domain, when the elastic the wave frequency is in the attenuation domain, elastic wave cannot propagate in the periodic medium. In addition, even if the elastic wave attenuation in frequency domain, after the spread of periodic structure with special design of elastic wave with directional features, namely wave energy transfer only along some direction, vibration in the other direction. The blind the direction of attenuation domain can wave characteristics and wave propagation, can be designed with vibration isolation function, periodic structure. These periodic structure can be applied to the environmental vibration in civil engineering and seismic isolation From them. The purpose of this study is through systematic research on this type of periodic structure, for the civil engineering vibration (vibration) method and puts forward a new idea. This paper through theoretical research, research methods of numerical simulation and other research results of the comparison, using series expansion technique and the finite element method, solving the different forms of cycle the structure of the dispersion curve. Then, by using the finite element method, establish the analysis model and reasonable boundary conditions, and then analyzes the various two-dimensional scattering of three-dimensional periodic structure. The experimental results of the author and other than that, the correctness of the theoretical results and the attenuation domain. The existence of innovations of this paper the main:
(1) the theory of periodicity in solid physics is proposed to analyze pile soil interaction. The concept of attenuation domain is used to explain the dispersion characteristics of periodic piles on elastic waves, and the attenuation characteristic of periodic piles is applied to achieve the attenuation of environmental vibration.
(2) the attenuation domain pile and periodic cycle hollow piles, and the factors influencing the attenuation domain were studied; the elastic modulus of soil is disclosed, the radius and the periodic constant pile effect on periodic pile pile attenuation domain, easy to draw a conclusion that common intermediate frequency vibration isolation size.
(3) the period of filling pile of the in-plane and out of plane attenuation domain, and the influence factors of attenuation domain were analyzed for the period of filling pile; the rationality of attenuation domain are explained by the local resonance mechanism and Prague scattering mechanism, the locally resonant period of filling pile is extended to low-frequency vibration.
(4) the attenuation and directional propagation characteristics of periodic fractal row piles are theoretically studied and numerically simulated, revealing the influence of algebra and filling rate on the attenuation region of periodic fractal piles.
(5) a periodic wave barrier with three dimensional vibration isolation (earthquake) ability is designed to provide a new idea for environmental vibration reduction and isolation of ground motion.
Through this research, not only can understand the periodic structure of the elastic wave scattering mechanism and damping effect, but also to reveal the periodic pile soil pile interaction mechanism, the energy conversion of elastic wave in between pile and soil and dissipation mechanism, establish a periodic row of piles in artificial vibration under the theoretical analysis and model the design method, and design a new type of wave barrier, have very important significance.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU352.1

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