Response of Base-Isolated USC Hospital Building in Northridge Earthquake
Publication: Journal of Structural Engineering
Volume 126, Issue 10
Abstract
The base-isolated University of Southern California (USC) hospital building experienced strong motion during the 1994 Northridge earthquake. California Strong Motion Instrumentation Program data of the response are available for performance evaluation. The objective of this study is to evaluate the seismic performance of the base-isolated USC hospital building during the 1994 Northridge earthquake. A nonlinear analytical model of the USC hospital building is developed and verified using system identification. The response computed, using the presented analytical modeling techniques, is verified using recorded data. Structural behavior during the Northridge earthquake is evaluated in detail. The base-isolated USC hospital building performed well and reduced the response when compared to a fixed-base structure. The free-field acceleration was 0.49g and peak foundation/ground acceleration was 0.37g. The peak roof acceleration was reduced to 0.21g, nearly 50% of the peak ground acceleration. The peak drift was <30% of the code specification. The bearings yielded and dissipated energy (20%). The superstructure was elastic due to the effectiveness of base isolation. The building is expected to perform well in future earthquakes similar to those used in the original design.
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References
1.
Asher, J. W., Hoskere, S., Ewing, R., Van Volkinburg, D. R., Mayes, R., and Button, M. ( 1995). “Seismic performance of the base isolated USC university hospital in the 1994 Northridge earthquake.” Proc., ASME Pressure Vessels and Piping Conf., Vol. 319, New York, 147–154.
2.
Dynamic Isolation Systems (DIS). ( 1989). “Test results for seismic isolation bearings for the USC university hospital building.” Rep. No. 5822-68, Calif.
3.
Earthquake Engineering Research Institute (EERI). ( 1996). “Northridge earthquake of January 17, 1994.” Earthquake spectra, 2, 248.
4.
Kelly, J. M. ( 1993). Earthquake resistant design with rubber, 1st Ed., Springer, New York.
5.
Ljung, L. ( 1987). System identification, Prentice-Hall, Englewood Cliffs, N.J.
6.
Nagarajaiah, S. ( 1999). “System identification of base isolated USC hospital building from recorded response.” Proc., 17th Int. Modal Anal. Conf., SEM, Fla., 159–165.
7.
Nagarajaiah, S., Reinhorn, A. M., and Constantinou, M. C. ( 1991a). “3D-BASIS: Nonlinear dynamic analysis of three dimensional base isolated structures—Part II.” Rep. No. NCEER-91-0005, Nat. Ctr. for Earthquake Engrg. Res., State University of New York, Buffalo.
8.
Nagarajaiah, S., Reinhorn, A. M., and Constantinou, M. C. (1991b). “Nonlinear dynamic analysis of 3-D-base-isolated structures.”J. Struct. Engrg., ASCE, 117(7), 2035–2054.
9.
Nagarajaiah, S., and Sun, X. ( 1995). “Response of base isolated buildings during the 1994 Northridge earthquake.” Proc., SMIP95 Seminar, 41–55.
10.
Nagarajaiah, S., and Sun, X. ( 2000). “Response of base isolated buildings in the 1994 Northridge earthquake.” Rep. No. 51, Rice University, Houston.
11.
Park, Y. J., Wen, Y. K., and Ang, A. H. S. ( 1986). “Random vibration of hysteretic systems under bi-directional ground motions.” Earthquake Engrg. Struct. Dyn., 14(4), 543–557.
12.
Shakal, A., et al. ( 1994). “CSMIP strong motion records from the Northridge earthquake of 17 January 1994.” Rep. No. OSMS 94-07, Calif. Strong Motion Instrumentation Program, California Department of Conservation, Calif.
13.
Wilson, E. L., Hollings, J. P., and Dovey, H. H. ( 1975). “ETABS—Three dimensional analysis of building systems.” Rep. No. UCB/EERC—75/13, Earthquake Engrg. Res. Ctr., University of California, Berkeley, Calif.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 126 • Issue 10 • October 2000
Pages: 1177 - 1186
History
Received: May 17, 1999
Published online: Oct 1, 2000
Published in print: Oct 2000
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