Sensitivity analysis of mass ratio effect on settlement and seismic response of shallow foundation using numerical simulation

Abstract

Structural inertial interaction is a representative the effect of dynamic soil–foundation–structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FSv), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FSv, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavilyloaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems. © 2023 Techno-Press, Ltd.