3D, fully-coupled, nonlinear numerical simulations of soil-foundation-mitigation-structure (SFMS) systems were performed in OpenSEES using a state-of-the-art soil constitutive model (PDMY02). The soil constitutive model was calibrated with a series of monotonic and cyclic triaxial tests and a free-field centrifuge test. The fixed-base structural models and fuses were calibrated based on beam-column component tests and hammer impact tests. Subsequently, we performed numerical simulations of centrifuge tests involving potentially inelastic multi-degree-of-freedom structures founded on liquefiable soil profiles when unmitigated and mitigated with densification. The predicted global response of the SFMS system was highly sensitive to the soil parameters and the soil-foundation interface. Overall, numerical results compared fairly well with experimental measurements in terms of accelerations and excess pore pressures in soil and accelerations transferred to the superstructure. The accuracy of the predicted foundation settlement and tilt improved for thinner liquefiable deposits or densified ground, with a smaller contribution from volumetric strains (in particular sedimentation).