Soil–Structure Interaction Effects on Seismic Performance and Earthquake-Induced Losses in Tall Buildings

AbstractThis paper evaluated the seismic performance of hypothetical tall buildings by estimating intensity measures, engineering demand parameters, and earthquake-induced losses using a soil–structure interaction (SSI) numerical framework. Numerical models for 40-story buildings were developed using OpenSees to study their seismic performance under the following modeling and building configuration conditions: (1) fixed-base structural model, (2) model including SSI effects, (3) fixed-base model with shear walls, and (4) model including shear walls and considering SSI effects. The buildings were assumed to be supported on subsurface conditions typical of downtown Los Angeles. The natural period of the soil profile was parametrically studied; the larger its natural period, the lower were the seismic demands of the building. The inclusion of shear walls caused a reduction of the natural period of the building and computed settlements in relation to the buildings without a shear wall system. Considering SSI effects in the modeling approach changed the computed seismic demands of the tall buildings in terms of maximum interstory drifts, peak story horizontal accelerations, and seismic-induced settlements. Computed median direct economic losses for the 2,475-year mean return period increased as much as 33% by considering SSI effects in the numerical analyses in relation to building losses ignoring those effects.