Abstract
Earlier research on seismic response modification coefficients predominantly relied on two-dimensional (2D) nonlinear analysis with uniaxial seismic loading and overlooked the consideration of structural overstrength. This study thus aims to address the limitations in the earlier research by assessing the force-based seismic design approach of building codes in which the elastic seismic forces and deformation demands are adjusted through the response modification coefficients to arrive at an economical design. To meet this objective, four multi-story steel buildings with heights ranging between eight to twenty stories are carefully designed to avoid unnecessary overstrength and to ensure fair assessment of design coefficients. Three-dimensional inelastic analyses are performed using a detailed fiber-based modeling approach involving incremental static analyses and multi-record bidirectional incremental dynamic analyses (MBIDAs) to assess the response modification coefficients. The results of the inelastic analyses revealed a safety margin of 34% to 45% on the coefficients specified in the design codes. The fragility functions derived using MBIDA results confirmed the satisfactory seismic performance of the benchmark structures at different intensity levels. The findings of this study reflect the potential to safely revise the response modification coefficients, providing designers with opportunities for design optimization.
Original language | English |
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Article number | 108869 |
Journal | Journal of Constructional Steel Research |
Volume | 221 |
DOIs | |
Publication status | Published - Oct 2024 |
Keywords
- Bidirectional earthquake loading
- Moment resisting frames
- Response modification coefficients
- Seismic design
- Steel buildings
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Mechanics of Materials
- Metals and Alloys