The American Society of Civil Engineers (ASCE) Standard 41-06 Supplement No.1 (2007) assists engineers in modeling and evaluating the non-linear behavior of structures till collapse. Different levels of conservatism were used throughout the standard to produce modeling parameters for different structural elements, which leads to inconsistencies at the system level. Task to update current ASCE 41-06 provisions pertaining to RC structures is now handled by ACI (American Concrete Institute) committee 369 entitled “Seismic Repair and Rehabilitation”. This study is a part of ACI 369 committee’s effort. Existing provisions for non-linear analysis are re-assessed in this study for both rectangular and circular reinforced concrete columns. A database of 490 column tests was compiled for this project. Median rather than conservative estimates of non-linear modeling parameters were produced to achieve “best” estimates of structural behavior. Proposed modeling parameters show improved fit with experimental data over existing parameters. Data necessary for selection of acceptance criteria are provided. / text

This paper provides an assessment of the seismic performance of a code-designed buckling restrained braced frame building using the performance-based analysis procedures prescribed in ASCE 41-06. The building was designed based on the standards of the ASCE 7-05 for a typical office building located in San Francisco, CA. Nonlinear modeling parameters and acceptance criteria for buckling restrained brace components were developed to match ASCE 41-06 design standards for structural steel components, since buckling restrained braces are not currently included in ASCE 41-06. The building was evaluated using linear static, linear dynamic, nonlinear static and nonlinear dynamic analysis procedures. This study showed that the linear procedures produced more conservative results, with the building performing within the intended Life Safety limit, while the nonlinear procedures predicted that the building performed closer to the Immediate Occupancy limit for the 2/3 maximum considered earthquake hazard. These results apply to the full maximum considered earthquake hazard as well, under which the building performed within the Collapse Prevention limit in the linear analysis results and within the Life Safety limit in the nonlinear analysis results. The results of this paper will provide data for the engineering profession on the behavior of buckling restrained braced frames as well as performance based engineering as it continues to evolve.