Fully Explicit Time-Domain Numerical Algorithm and Application for Fluid-Saturated Porous Media Considering Inertial Coupling

In the current study, u-p dynamic equation considering inertial coupling was innovatively developed. A fully explicit algorithm of the time-domain analysis on near-field wave propagation in the fluid-saturated porous media (FSPM) was established. The stability interval of the algorithm was proposed. The fully explicit staggered algorithm was combined with the transmission artificial boundary. The accuracy of the established algorithm was verified through the comparative study between the numerical results and correspondence analytical results. The numerical investigation of both the dynamic response of FSPM and underground structures in FSPM was conducted. A user-defined element for dynamic analysis considers the effect of inertial coupling of saturated porous media is developed in ABAQUS. The numerical results show that the influence of inertial coupling on the dynamic response of FSPM varies with the input mode of dynamic load. The obvious effect of inertia coupling on soil can be captured when the seismic P-wave is input. And the effects on the dynamic response amplitude of FSPM and underground structures in FSPM are various among the coupling density coefficients. Besides, the time for underground structures or soil to reach the amplitude of dynamic response will be shortened with the effect of inertia coupling.