S. A. Sadrnejad - Professor, Civil Eng. Dep., K.N. Toosi University of technology, Tehran
S.A. Ghoreishian Amiri - Ph. D. Student, Civil Eng. Dep., K.N. Toosi University of technology, Tehran
A. Tafazzoli - Master of science, Civil Eng. Dep., K.N. Toosi University of technology, Tehran

The differential equations governing the 3D dynamic behavior of saturated porous media are derived and solved with numerical algorithms. The finite elements and Newmark's methods are used to discrete the differential equations in spatial and time domain respectively. A cubic element with 20- nodes and 68 degree of freedom is applied for finite element approximation. The isoparametric and superparametric simulations have been used for unknown deformations and pore pressures respectively. The material nonlinearity is included with subloading surface model with rotational hardening. The skyline Gaussian elimination method is applied for solving the linear matrix equation. The proposed numerical solution and subloading surface theory to describe the constitutive behavior of soil have been implemented as the computer code SMAT. Predictions made by SMAT are verified with several examples including test results and analytical solutions. Reasonable agreements are achieved.

fully coupled, dynamic analysis, saturated porous media, subloading surface theory