Collapse Prevention Seismic Performance Assessment of New Eccentrically Braced Frames using ASCE 41
Matthew S. Speicher, John L. Harris
This paper presents the results of a seismic performance assessment using ASCE 41-06 for six eccentrically braced frames (EBFs) designed in accordance with the 2012 International Building Code. The correlation between ASCE 7-10 and ASCE 41-06 is investigated to compare the seismic performance anticipated by the two standards. Three archetype buildings (4-, 8-, and 16-story) with EBFs along one principal direction are designed for seismic effects: (1) once using the equivalent lateral force (ELF) procedure and (2) a second time using the response spectrum analysis (RSA) procedure. Performance assessments of the frames are conducted using four analysis procedures, static and dynamic analyses performed under both linear and nonlinear analysis regimes. Linear analysis results indicate performance issues in the columns and no issues in the links. In contrast, the nonlinear analysis results show that the links in the 8- and 16-story frames consistently fail to meet the assessment criteria due to significant concentrations of ductility demands. Furthermore, the RSA-designed frames generally perform poorer than their ELF-designed counterpart frames. The contributing factors to the noted performance issues with regards to ASCE 41 are investigated and recommendations are made on how to alter the performance outcome.