波浪作用下层状海床孔隙水压力响应的计算方法

Analysis method for pore pressure in a multi-layered seabed under wave loading

采用Biot动力理论研究波浪荷载作用下层状海床孔隙水压力动力响应问题。土体位移和孔隙水压力采用2个标量势和一个矢量势表示。利用Fourier变换将Biot动力方程解耦成势函数表示的Helmholtz方程。利用边界条件及层状土层间连续条件,推导出传递、透射矩阵(TRM),进而得到位移、孔压、应力在变换域内的基本解,利用Fourier逆变换得到时域内的结果。给出了具体算例分析波浪和土层性状对孔隙水压力响应值的影响。

Dynamic response of pore pressure in a multi-layered poroelastic seabed is studied by use of the Biot's theory.The displacements of the solid skeleton and the pore pressure are expressed in terms of two scalar potentials and one vector.Then,the Biot's dynamic equation can be solved by using the Fourier transformation and reducing to Helmholtz equations that the potentials satisfy.In order to obtain the general solutions for the multi-layered poroelastic seabed in the frequency-wavenumber domain,the transmission and reflection matrices(TRM) method is used to form the equivalent stiffness.Using the boundary conditions and continuous conditions,the frequency-wavenumber domain solutions are obtained.Finally,the time-space domain solutions for the multi-layered poroelastic seabed are obtained by means of the inverse Fourier transformation with respect to the horizontal coordinate.The effects of wave and soil characteristics on the wave-induced seabed pore pressure are investigated.