IDA Capacity Curves: The Need for Alternative Intensity Factors

Incremental dynamic analysis (IDA) has recently emerged as an alternative approach to investigate inelastic limit states in performance-based seismic engineering. IDA requires a series of nonlinear-time history analyses at increasing intensity levels of the same ground motion. The intensity of the earthquake load is typically expressed in terms of the first mode spectral acceleration. In this study the validity of such an intensity measure is investigated. IDA is applied to an existing six-story steel moment-frame building. Two sets of ground motions representing far-fault and near-fault records are considered separately to study the influence of different seismic source characteristics on the outcomes of the IDA. The study reveals that first mode spectral acceleration, Sa(T1,5%), is an inadequate and incomplete measure of seismic intensity in the context of generating IDA capacity curves. It is concluded that alternative intensity measures are needed to make IDA more meaningful in seismic assessment. A preliminary investigation utilizing spectral magnitudes from constant-ductility inelastic spectra as a measure of seismic intensity is reported in this paper.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0784407533
• Corporate Authors:

  American Society of Civil Engineers

  International Headquarters, 1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400

  Structural Engineering Institute

  American Society of Civil Engineers
  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Kunnath, Sashi K
  • Kalkan, Erol
• Conference:
  • Metropolis and Beyond
  • Location: New York NY, United States
  • Date: 2005-4-20 to 2005-4-24
• Publication Date: 2005

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; References; Tables;
• Pagination: 9p
• Monograph Title: Metropolis and Beyond: Proceedings of the 2005 Structures Congress and the 2005 Forensic Engineering Symposium, April 20-24, 2005, New York, NY

Subject/Index Terms

• TRT Terms: Earthquake engineering; Earthquakes; Electromagnetic spectrum; Magnitude; Measurement; Multistory structures; Seismicity
• Uncontrolled Terms: Constant ductility inelastic spectra; First mode spectral acceleration; Incremental dynamic analysis; Intensity; Performance based design; Steel moment frames
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics; I43: Rock Mechanics;

Filing Info

• Accession Number: 01033708
• Record Type: Publication
• ISBN: 0784407533
• Files: TRIS
• Created Date: Sep 29 2006 10:38AM