群桩基础引发饱和地基振动的近似解析解

建立了饱和半空间-群桩基础耦合动力近似解析模型，其中基桩考虑为欧拉梁，饱和地基采用Biot两相介质动力控制方程，二者在频率-波数域中利用桩-土相互作用点处的饱和地基柔度矩阵进行耦合，并采用快速傅里叶逆变换获得频域解答。分析了饱和地基中群桩基础的动力阻抗及刚性承台上施加简谐振动荷载时群桩基础引起的饱和地基振动响应。研究结果表明，荷载类型、激振频率以及地基渗透系数对饱和地基位移和孔压响应有明显影响。特别的，群桩基础动力阻抗峰值频率会随着地基渗透系数的增加而增大。

Approximate analytical solution on vibrations of saturated ground induced by pile foundations

An approximate analytical model has been established in this paper to study dynamic interactions between the saturated soil and the pile group with assumption of poroelastic half-space. The piles are modeled as Bernoulli-Euler elastic beams, and the saturated half-space is governed by Biot’s dynamic equations. The pile beams and the saturated half-space are coupled through receptance matrix established at pile/soil interaction points in frequency-wavenumber domain. Results are obtained by fast Fourier transform. The dynamic impedances of the pile group have been analyzed. Meanwhile, the results demonstrated that the type and frequency of the excitation force and the soil permeability have significant influences on displacement and pore pressure responses of the saturated ground. Especially, it is noted that peak frequencies of pile-foundation impedance increase along with the increasing of soil permeability.