Closer Look at the Drift Demand Spectrum
Publication: Journal of Structural Engineering
Volume 128, Issue 7
Abstract
This technical note explores the physical and mathematical basis for the drift demand spectrum proposed in the 1990's by Iwan, and reveals several unexpected features of the original mathematical formulation. It is shown that the solution presented by Iwan does not provide the drift response of an isolated uniform shearbeam; instead, the solution corresponds to an analytical model in which the cantilevered shearbeam is attached to external springs and dampers anchored to a fixed reference point. Two alternative mathematical formulations are presented based on more realistic analytical models, and the results are compared with those obtained by Iwan's formulation. Advantages and disadvantages of all three formulations are discussed.
Get full access to this article
View all available purchase options and get full access to this article.
References
Clough, R. W., and Penzien, J. (1993). Dynamics of structures, 2nd Ed., McGraw-Hill, New York.
Collins, K. R., Wen, Y. K., and Foutch, D. A.(1996). “Dual-level seismic design: A reliability-based methodology.” Earthquake Eng. Struct. Dynam., 25, 1433–1467.
Doyle, J. F. (1997). Wave propagation in structures, 2nd Ed., Springer, New York.
Iwan, W. D. (1994). “Near-field consideration in specification of seismic design motions.” Proc., 10th European Conf. on Earthquake Engineering, A. A. Balkema, Rotterdam, The Netherlands, 1, 257–267.
Iwan, W. D.(1997). “Drift spectrum: Measure of demand for earthquake ground motions.” J. Struct. Eng. 123(4), 397–404.
Kim, J., and Collins, K. R. (1999). “Uniform hazard drift demand spectra.” Proc., 1st Int. Conf. on Advances in Structural Engineering and Mechanics (ASEM'99), Techno-Press, Seoul, Korea.
Kosloff, R., and Kosloff, D.(1986). “Absorbing boundaries for wave propagation problems.” J. Comput. Phys., 63, 363–376.
Information & Authors
Information
Published In
Copyright
Copyright © 2002 American Society of Civil Engineers.
History
Received: Aug 29, 2000
Accepted: Sep 27, 2001
Published online: Jun 14, 2002
Published in print: Jul 2002
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.