Considerable research has been conducted worldwide to assess the unexpected damage to welded steel moment-frame buildings during the 1989 Loma Prieta, 1994 Northridge, and 1995 Hyogo-ken Nanbu earthquakes, as well as to find effective and economical remedies that can be incorporated into analysis, design, and construction practices. A major six-year program has been undertaken with the sponsorship of the U.S. Federal Emergency Management Agency (FEMA) to synthesize and interpret the results of this research, and to conduct additional investigations to develop reliable, practical, and cost-effective guidelines for the design and construction of new steel moment-frame structures, as well as for the inspection, evaluation and repair or upgrading of existing ones. Topics investigated as part of this program include (1) performance of steel buildings in past earthquakes; (2) material properties and fracture issues; (3) joining and inspection; (4) connection performance; (5) system performance; (6) performance prediction and evaluation; and (7) social, economic, and political impacts. The project utilizes a performance-based engineering framework and addresses issues pertaining to various types of steel moment-resisting frames including those utilizing welded, bolted, and partially restrained connections. The guidelines are applicable to regions of low, medium, and high seismicity throughout the United States. This paper reviews the overall organization and management of this program of research, guideline development, training and peer evaluation, the scope of the investigations undertaken, and the general organization and contents of the guidelines developed.
Simplified Time-Dependent Column Shortening Analysis in Special Reinforced Concrete Moment Frames
