Numerical Study on the Seismic Response of Fluid-Saturated Porous Media Using the Precise Time Integration Method

Abstract

The seismic response behavior of fluid-saturated porous media (FSPM) has been a critical subject in the area of soil dynamics and geotechnical earthquake engineering. In this paper, the numerical study of the seismic response of the FSPM is performed based on the u-p dynamic formulation. A time-stepping explicit algorithm for the numerical solution to the u-p dynamic formulation is developed. The precise time integration method is adopted in the algorithm to improve the computational accuracy. The transmitting artificial boundary is used to describe the energy radiative effect of the wave motion in the FSPM. The numerical results indicate that the time-stepping explicit algorithm developed in the current study is applicable and effective for the numerical solution of the dynamic problems of the FSPM based on the u-p dynamic formulation. Furthermore, parametric studies are performed to investigate the effect of the permeability coefficient, elastic modulus of the solid skeleton and porosity on the dynamic response of the FSPM. The analyses show that the permeability coefficient value has a negligible effect on the solid skeleton displacement but has a noticeable impact on the pore fluid pressure. With the decrease of the permeability coefficient value, the peak pore pressure increases remarkably. The elastic modulus of the solid skeleton has an important effect on the solid skeleton displacement and pore fluid pressure. With the decrease of the magnitude of elastic modulus, the solid skeleton displacement and pore fluid pressure increase remarkably. The porosity value has an insignificant effect on the solid skeleton displacement but has a significant impact on the pore fluid pressure. With the increase of the porosity value, the peak pore pressure decreases significantly.