Comparison of the seismic performance of multistory and multi-tiered braced frames

A. Agarwal, L. A. Fahnestock

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Steel braced frames are commonly used as lateral force resisting systems in seismic applications. In the case of tall single-story steel buildings, it is more economical to use multi-tiered braced frames (MT-BFs) in which the braced bay is divided into multiple panels over the height. In contrast to multi-story braced frames (MS-BFs), MT-BFs lack intermediate out-of-plane supports or diaphragms between the base and the roof. While the primary energy dissipation mechanism in both systems is brace inelastic axial response, the unique conditions in MT-BFs have been shown to cause inelastic drift concentration in one tier that can lead to column instability from combined axial and flexural demands. This study uses nonlinear static analysis to quantify the differences in seismic demand and behavior of the two configurations. The results for the 2-tier/story frames clearly demonstrate the need to consider flexural demands in MT-BF column design. Further, while column buckling occurs at lower roof drifts for the MT-BFs, the difference is more pronounced for the 2-tier/story frames than the 3-tier/story frames that have essentially the same response. In general, the results show that the overall demand in columns is higher in MT-BFs, but column instability can still occur in MS-BFs.

Original languageEnglish (US)
Title of host publication11th National Conference on Earthquake Engineering 2018, NCEE 2018
Subtitle of host publicationIntegrating Science, Engineering, and Policy
PublisherEarthquake Engineering Research Institute
Pages1482-1486
Number of pages5
ISBN (Electronic)9781510873254
StatePublished - 2018
Event11th National Conference on Earthquake Engineering 2018: Integrating Science, Engineering, and Policy, NCEE 2018 - Los Angeles, United States
Duration: Jun 25 2018Jun 29 2018

Publication series

Name11th National Conference on Earthquake Engineering 2018, NCEE 2018: Integrating Science, Engineering, and Policy
Volume3

Conference

Conference11th National Conference on Earthquake Engineering 2018: Integrating Science, Engineering, and Policy, NCEE 2018
Country/TerritoryUnited States
CityLos Angeles
Period6/25/186/29/18

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

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