Explicit-implicit staggered algorithm of u-p formulation for dynamic problems of fluid-saturated porous media

In order to describe the dynamic response of fluid-saturated porous media with the formulation of soil displacement u and pore pressure p, an explicit-implicit staggered algorithm is proposed based on the central difference method and precise time-integration method. The Gauss integration, trapezoid integration and the second-order Lagrange interpolation polynomial are utilized to simulate the soil displacement in the inhomogeneous term of the pore pressure formulation, respectively. Furthermore, an acubic spline interpolation method is developed based on the precise time-integration method, and it can avoid the computation of the inverse matrixes involved coupling velocity term. Finally, some cases are adopted to verify the proposed method. The computational results obtained by the proposed method have a good agreement with those by the Zienkiewicz's explicit-implicit method, indicating the effectiveness of the proposed approach.