Chapter 09-Seismic Design Of Steel Structures.pdf

Chapter 9
Seismic Design of Steel Structures
Chia-Ming Uang, .
Professor of Structural Engineering, University of California, San Diego
Michel Bruneau, ., .
Professor of Civil Engineering, State University of New York at Buffalo
Andrew S. Whittaker, ., .
Associate Professor of Civil Engineering, State University of New York at Buffalo
Key-Chyuan Tsai, ., .
Professor of Civil Engineering, National Taiwan University
Key words: Seismic Design, Steel Structures, NEHRP mended Seismic Provisions, AISC Seismic Provisions, R
Factor, Ductility, System Overstrength, Capacity Design, 1994 Northridge Earthquake, Moment-Resisting
Frames, Brittle Fracture, Moment Connections, Concentrically Braced Frames, Buckling, Braces,
Eccentrically Braced Frames, Links.
Abstract: Seismic design of steel building structures has undergone significant changes since the Northridge,
California earthquake in 1994. Steel structures, thought to be ductile for earthquake resistance, experienced
brittle fracture in welded moment connections. The latest AISC Seismic Provisions reflect the significant
research findings that resulted from the Northridge earthquake. This chapter first starts with a description of
the seismic design philosophy, the concept of system parameters (R, Cd, and Ωo) and capacity design.
Background information for the seismic requirements in the AISC Seismic Provisions of Moment Frames,
Concentrically Braced Frames, and Eccentrically Braced Frames are then presented. Design examples are
provided for each of the three structural systems.
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9. Seismic Design of Steel Structures 411
Introduction ratio, respectively. If the structure is designed to
respond elastically during a major earthquake,
the required elastic base shear ratio, Ceu, would
General be high. For economical reasons, the NEHRP
mended Provisions take advantage of the
Steel is one of the most widely used structure's inheren