James O. Malley
"Phase II of the
FEMA/SAC steel project: Development of seismic design criteria and inspection
moment resisting steel frame (WMSF) construction had been the system
of choice for major commercial buildings in California for more than
twenty-five years. This was largely due to the perceived capability of this
system to provide superior earthquake performance as well as the relatively
simple task of designing, detailing, and constructing these structures. Following
the Northridge earthquake, unanticipated
brittle fracture damage was found in a number
of these structures. Emergency changes to
the Uniform Building Code deleted prescriptive detailing provisions, substituting
in their place performance specifications for the design of framing connections.
This made design and construction of WMSF structures complex and difficult.
The SAC Joint Venture, a partnership of
the Structural Engineers Association of California, the Applied Technology Council,
and California Universities for Research in Earthquake Engineering was formed
to perform needed research and develop practical design criteria for these structures.
In August, 1995, FEMA 267 (SAC, 1995a.)
was published, providing criteria for complying with the emergency code change.
While FEMA 267 provided much urgently needed
information, design of steel frame structures remained a complex task. The SAC
Joint Venture is currently engaged in the second phase of research
into the behavior of MRSF structures, and development of engineering and inspection
guideline documents. Scheduled for completion in late 1999, these documents
will include the following individual publications:
Post-Earthquake Guidelines for Welded
Moment Resisting Steel Frame Buildings
2. Evaluation and Upgrade Guidelines for Moment
Resisting Steel Frame Buildings
3. Design Guidelines for New Moment Resisting
Steel Frame Buildings
4. Quality Assurance and Control Guidelines
for Steel Frame Construction
addition to the guideline publications indicated above, a series of State-of-the-Art
reports will be prepared containing a summary of the technical basis upon which
the guidelines are based. These State-of-the-art
reports will include reports on past performance of steel buildings in earthquakes,
materials and fracture, welding and inspection, connection performance, system
performance, and performance prediction and evaluation.