Develop Recommended Procedures for Performance and Evaluation of Steel Moment Resisting Frame Buildings 

Principal Investigator: Douglas Foutch 
University of Illinois at Urbana-Champaign 

This task will address the following objectives: 

- Provide recommendations as to what is the "most accurate" method of modeling and analyzing a frame structure considering various hysteretic behavior, effective damping, and participation of gravity frames. The best model will then be used to establish bias factors which will be combined with bias factors developed in Sub-Tasks 5.5.2, 5.5.3, and 5.5.5. 

- The reliability, or safety, of damaged frames will be evaluated. Reductions in safety margin for frames under various conditions of damage will be investigated. 

- The behavior of frames designed by the 1994 UBC (approximately equivalent to the 1988 UBC), 1997 UBC and 1997 NEHRP provisions will be investigated to determine the annual probability of exceedance for the Immediate Occupancy and Incipient Collapse States of the nine SAC model buildings. 

- The behavior of frames designed to the provisions of the 1973 UBC, 1979 UBC and 1988 UBC (1988 & 1994 S/B are about the same) will be investigated to determine the annual probability of exceedance for the Immediate Occupancy and Incipient Collapse of the nine SAC model buildings. 

- Results from the SP and CP teams to determine if weak panel zones, strong-beams and weak columns, weak column splices, and other features will result in substantial decrease in safety margin and will be used to develop indicators for a "rapid evaluation" methodology such as FEMA 178. 

- The effects of structural redundancy on frame reliability will be investigated. 

The detailed breakdown of the technical activities in this task are provided in the workstatement available here.