列车荷载下轨道系统-层状横观各向同性饱和地基动力响应  

Dynamic response of track system-layered transversely isotropic saturated subgrade to train loads

作　　者：叶俊能[1] 

机构地区：[1]宁波市轨道交通工程建设指挥部,浙江宁波315012

出　　处：《岩土力学》2010年第5期1597-1603,1614,共8页Rock and Soil Mechanics

基　　金：宁波市重大(重点)科研攻关项目资助(No.2009C50004);宁波市自然科学基金项目资助(No.2007A610062)

摘　　要：基于Biot波动理论,构建列车荷载-轨道系统-双层状横观各向同性饱和地基模型,将模型分为上覆路轨系统和地层系统。对上覆路轨系统和地层系统处理,并利用双重Fourier变换技术,在变换域中将横观各向同性饱和地基动力响应的求解简化为求解一个6阶控制方程的特征值问题,进而得到了列车荷载作用下双层横观各向同性饱和地基力响应的解析结果。利用离散Fourier逆变换得到数值计算结果,重点分析了上下土层的刚度和泊松比对位移和孔隙水压力和剪切应力响应的影响,结果表明,上、下土层刚度差异对地基动力响应有较大影响,土层各向异性参数中模量的影响较泊松比大。计算结果可为软土路基加固深度的确定提供理论依据。Based on Biot＇s dynamic poroelastic theory,a system of rail pad,sleeper,ballast and double layers of transversely isotropic saturated subgrade is proposed,in which the system can be decomposed as a track system and a double layered soil system.Applying the double Fourier transformation technique to the track system and the soil layer system,the governing equation of track-layered transversely isotropic saturated subgrade system is simplified as an eigenvalue problem for solving a 6 order governing equation.The solutions of the dynamic response of track system-double layered transversely isotropic saturated subgrade to train loads are derived in the transformation domain.Numerical results are obtained by using the inverse fast Fourier transform（IFFT）;and then the IFFT are used to analyze the influence of the modulus and Poisson ratio of the first and the second layer of soil on the displacement,pore pressure and shear stress.It is shown that there are great influence of the stiffness of soil layers on the dynamic response;and the influence of modulus are greater than that of Poisson ratio.The computational results can serve as a reference for determination of the reinforcement depth in the soft subgrade.

关 键 词：列车荷载 轨道系统 横观各向同性 饱和地基 动力响应 

分 类 号：U21[交通运输工程—道路与铁道工程]