Date of Graduation
Master of Science in Civil Engineering (MSCE)
Michelle L. Bernhardt
Gary S. Prinz
Second Committee Member
Clinton M. Wood
Dynamic Analysis, Eccentrically Braced Frames, Nonlinear Modeling, Seismic Response, Shallow Foundations, Soil-structure Interaction
The importance of soil-structure interaction (SSI) effects on the seismic response of
buildings has been long recognized and has been researched for over 40 years. However, SSI
analysis has only been applied in a few building projects because the fixed base condition is
considered to provide a conservative estimation for the response of buildings under seismic loads.
This assumption of a fixed base condition adopted by practitioners is not always conservative or
cost-effective, especially for rigid buildings over soft soils. Additionally, for the case of ductile
steel frames with eccentric configurations, the influence of SSI on their seismic performance has
not been investigated.
In this study, the seismic performance of eccentrically braced frames (EBFs) considering
SSI effects is investigated using analytical models. Background information and modern
guidelines available to consider SSI in the seismic analysis of buildings are presented and
discussed. Following, a 3-story building with EBFs on shallow foundations is analyzed with and
without SSI. The beam on Winkler foundation approach is used to model the linear and nonlinear
soil-foundation interface behavior, considering linear-elastic, elastic-perfectly plastic, and
nonlinear springs. Inter-story drifts, residual drifts, link rotations, and axial load column demands
were similar for frames with flexible base and fixed base conditions when elastic and elastic-perfectly
plastic springs were used. However, when nonlinear springs were used, frames with a
flexible base showed a significant reduction in their responses in comparison to those observed for
the fixed base condition. As a result, a reduction in frame member sizes was possible and justified
through SSI analyses.
Buitrago Goyez, Luis Gerardo, "Soil-Structure Interaction Effects on the Seismic Response of Low-Rise Eccentrically Braced Frames" (2017). Theses and Dissertations. 2398.