二维周期排桩隔振技术应用于兰州中川国际机场的初探研究

Preliminary Study on the Vibration Isolation of Two-dimensional Periodic Piles Applied to Lanzhou Zhongchuan International Airport

为了克服传统隔振技术因需要在基础与地基之间埋置隔振装置从而削弱结构的整体性和限制隔振装置的更换等方面的不足,立足于屏蔽弹性波的新思想,基于周期结构的通禁带,采用数值模拟手段研究二维周期排桩结构的带隙特性及其对禁带频段内弹性波的抑制作用,并探讨将这种隔振新技术应用在兰州中川国际机场的新建航站楼与跑道之间来实现隔振时结构设计参数的选取规律。研究发现,对于相对刚度而言,在所选择的材料中,外层散射体钢和内层散射体混凝土及土体所组成的胞元具有最宽的弹性波衰减范围;减小晶格常数增大填充率或者构造含有两种晶格常数的胞元结构可获得更宽的弹性波衰减范围。研究结果可为中川国际机场的周期性排桩设计提供理论指导,从而精准地实现工程结构物的隔振需求。

The traditional vibration isolation technology requires the installation of isolation devices between the substructure and the foundation,which reduces the structural integrity and restricts the device replacement.In order to avoid these disadvantages of traditional isolation technology,this paper introduces the new concept of shielding elastic waves by periodic structures.The two-dimensional(2D)periodic piles with bandgap characteristics are studied through numerical simulations.The design principles for structural parameters of the 2D periodic piles are summarized in detail.This technique is applied to the vibration isolation of the runways to terminal buildings in Lanzhou Zhongchuan International Airport,and the selection of the parameters of the 2D periodic piles structure is detected.It is found that for the relative stiffness of the selected materials,the periodic piles structures with unit cell composed of the outer steel scatter,the inner concrete scatter and the soil matrix have the widest attenuation range of elastic waves.By decreasing lattice constants and increasing the filling rate or by constructing the cell structures with two lattice constants,a wider attenuation frequency range of the periodic piles structure for elastic waves can be obtained.The results have provided a theoretical guidance for the design of periodic piles at Lanzhou Zhongchuan International Airport so as to accurately realize the vibration isolation for engineering structures.