摘要
从饱和土Biot波动方程出发,基于二次形函数薄层法,将圆柱坐标系下饱和土的Biot轴对称波动方程在竖向进行离散,沿切向及轴向坐标分别进行Fourier级数分解和Hankel变换,得到饱和地基频域-波数域中的位移基本解,再利用Hankel逆变换和Fourier综合,求得频域柱坐标系下的位移表达。结合移动列车-轨道-地基的振动模型,对饱和地基上列车运行引起的地面振动进行了分析,讨论了动力渗透系数、孔隙率和动力流体粘滞系数等参数对地面振动传播与衰减的影响规律,并与弹性地基的振动衰减进行了比较。结果表明:在不同列车运行速度下,饱和地基和弹性地基的竖向位移振动响应差异较大;饱和土体的动力渗透系数、孔隙率和孔隙流体动力粘滞系数是影响地面振动的主要参数。
Based on Biot＇s wave propagation equation, the quadratic shape function TLM （thin-layer method） is adopted to derive the solution of Lamb＇s problem for saturated ground. The displacement expression in the frequency-wave number domain for saturated soil is obtained by dividing Biot＇s axisymmetric dynamic equation in vertical coordinates, and by the Fourier series decomposition in tangential coordinates and Hankel transform in axial coordinates. Then the inversion of Hankel transform and Fourier synthesis are used to get the displacement expression in the frequency domain. By a moving traintrack-ground interaction model, a parametric study is given to evaluate the ground vibration induced by a moving train on the saturated ground. The effect of the soil parameters （such as dynamic permeability coefficient, porosity and dynamic fluid viscosity coefficient） on the attenuation of ground vibration are investigated and discussed in detail. The amplitude attenuation of ground vibration is compared between elastic ground and saturated one. The results show that the vertical displacement responses for poroelastic medium are quite different from those for elastic medium at the different train speeds. It is also found that the dynamic permeability coefficient of soil, porosity and the fluid viscosity coefficient have great influence on ground vibration.
出处
《振动工程学报》
EI
CSCD
北大核心
2010年第2期179-187,共9页
Journal of Vibration Engineering
基金
国家自然科学基金重点项目(50538010)
国家自然科学基金项目(50678128
50878155)
关键词
饱和土
地面振动
列车-轨道-地基振动模型
动力GREEN函数
薄层法
saturated soil
ground vibration
train-track-ground vibration model
dynamic Green＇ functions
thin layeredmethod （TLM）
