列车荷载下上覆弹性层横观各向同性饱和地基的动力响应

Dynamic response of elastic layer on transversely isotropic saturated soil to train load

基于Biot多孔弹性介质的波动理论,构造了轨道、道碴、枕木及弹性层的横观各向同性饱和地基在列车荷载下的动力计算模型。利用Fourier变换,得到了列车荷载作用下横观各向同性软土地基上弹性层动力响应的解析结果。利用离散Fourier逆变换得到数值计算结果,分析了荷载速度、地基的各向异性参数、弹性层刚度系数及厚度对位移和孔压响应的影响。分析结果表明:弹性层对控制地基振动作用显著,地表振动幅值随荷载速度的增加而增大,软土的横向弹性模量对地表振动及土中孔压有较大影响。

A calculation model of dynamic response of transversely isotropic saturated soil under train load is proposed.Rail,rail pad,sleeper,ballast and elastic layer were added into the model.Based on Biot＇s dynamic poroelastic theory,the dynamic responses of elastic layer on transversely isotropic saturated soils generated by the train load is presented by using the Fourier transform.Numerical results are obtained by using the inverse fast Fourier transform（IFFT）;and then,they are used to analyze the influence of the moving load velocity,anisotropic parameter and stiffness coefficient of elastic layer on soil displacemen and pore pressure.The results show that the displacement amplitude increases with the increasing of the load velocity;and the elastic layer has great influence on ground vibration and pore pressure.