Coupled Soil-Structure Interaction Effects of Symmetric and Asymmetric Buildings In Urban Regions

This thesis deals with the response of idealized building clusters during earthquakes, their effect on the ground motion, and how individual buildings interact with the soil and with each other. We simulate the ground motion during the 1994 Northridge earthquake and focus on the coupled response of multiple simplified symmetric and asymmetric building models located within the San Fernando Valley and the Simi Valley. We use the Domain Reduction Method (DRM) in order to perform these simulations efficiently while recurrently modifying the models without having to redo the entire simulation every time. Numerical results show that the soil-structure interaction (SSI) effects vary with the number and dynamic properties of the buildings, their separation, and the impedance with respect to the soil. These effects appear as: (i) an increased spatial variability of the ground motion; and (ii) significant reductions in the buildings’ base motion at high frequencies, changes in the higher natural frequencies of the building-foundation systems and variations in the roof displacement, with respect to those of the corresponding rigid-base and single SSI models. Torsional coupling of the asymmetric structures combined with SSI effects are also investigated, and results, in comparison with the symmetric structures, are given.