Seismic Behavior and Retrofit of Outrigger Knee Joints
Publication: Journal of Bridge Engineering
Volume 12, Issue 5
Abstract
Experimental tests were conducted on six 1/3-scale specimens to define the vulnerabilities of existing outrigger bents under in-plane and out-of-plane seismic loading and to develop retrofit measures that address the identified vulnerabilities. The specimens represented knee joints in the SR 99 Spokane Street overcrossing in western Washington State but included deficiencies present in a number of older bridges. The as-built specimens failed at low ductility levels due to shear distress, low torsional strength of the outrigger beam, and reinforcement bond failures within the joint. Threshold principal tension stress values describing the expected condition of the joints were established and compared to values obtained by other researchers. Circular steel jackets were used to retrofit the as-built specimens. The retrofitted specimens developed plastic hinging in the column, with enhanced strength, energy, and ductility capacities. Design and detailing guidelines for retrofitting outrigger bents were proposed.
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Acknowledgments
The research presented in this paper was funded by the Washington State Department of Transportation. The assistance of the Washington State University engineering shops in making components for the retrofitted specimens is appreciated.
References
Ingham, J. M., Priestley, M. J. N., and Seible, F. (1994a). “Seismic performance of bridge knee joints. Volume I.” Rep. No. SSRP 94/12, Structural Systems Research, Univ. of California, Berkeley, San Diego.
Ingham, J. M., Priestley, M. J. N., and Seible, F. (1994b). “Seismic performance of bridge knee joints. Volume II.” Rep. No. SSRP 94/17, Structural Systems Research, Univ. of California, Berkeley, San Diego.
Ingham, M. J., and Sritharan, S. (2003). “Application of strut-and-tie concepts to concrete bridge joints in seismic regions.” PCI J., 48(4), 66–90.
NIST (1990). Performance of structures during the Loma Prieta Earthquake of October 17, 1989, NIST Special Publication 778, H. S. Lew, ed., U.S. Dept. of Commerce, Washington, D.C.
Priestley, M. J. N., Seible, F., and Calvi, G. M. (1996), Seismic design and retrofit of bridges, Wiley, New York.
Shattarat, K. N. (2004). “Seismic behavior and retrofit of outrigger knee joints.” Ph.D. dissertation, Washington State Univ., Pullman, Wash.
Stojadinovic, B., and Thewalt, C. R. (1995). “Upgrading bridge outrigger knee joint systems.” Rep. No. UCB/EERC-95/03, Earthquake Engineering Research Center, Univ. of California, Berkeley, Calif.
Zhang, H., Knaebel, P. J., Coffman, H. L., VanLund, J. A., Kimmerling, R. E., and Cuthbertson, J. G. (1996). Seismic vulnerability study of the SR 99 Spokane Street overcrossing, Washington State Dept. of Transportation, Olympia, Wash.
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© 2007 ASCE.
History
Received: Aug 30, 2004
Accepted: Jul 14, 2006
Published online: Sep 1, 2007
Published in print: Sep 2007
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