Three-Dimensional Earthquake Responses of Nuclear Containment Building Installed in Water-Saturated Soil Strata

In this study, 3-D earthquake responses of nuclear containment building installed in water-saturated soil strata are obtained using a rigorous model of the water-saturated two-phase porous medium. Impedances of a massless rigid foundation of the building and effective earthquake forces are obtained. Far-field region of soil is represented by a 3-D transmitting boundary, which is used for modeling the elastic waves radiating out to an infinite boundary in water-saturated soil strata overlaying rigid bedrock. Using 3-D finite elements for saturated two-phase porous medium, models are developed for the near-field region of soil. The transmitting boundary is combined with the finite-elements model of the near-field region. The impedances and effective earthquake forces are obtained from the numerical model of soil strata. Earthquake responses of the nuclear containment building subject to a 3-D ground motion (two horizontal and a vertical motions) are obtained. The building structures are modeled using a beam-stick model. The impedances of the foundation are combined with the structure model. The effective earthquake forces are applied to the combined model. Floor response spectra of pseudo-acceleration and time histories of acceleration are obtained, which can be used for an analysis of structure-equipment interaction.