Shear and Friction Response of Nonseismic Laminated Elastomeric Bridge Bearings Subject to Seismic Demands
Publication: Journal of Bridge Engineering
Volume 18, Issue 7
Abstract
Laminated elastomeric bridge bearings are commonly used in areas with low-to-moderate seismicity, although the applications are typically intended for service-level considerations such as thermal movements of the bridge superstructure. These components provide a potential source of displacement capacity frequently neglected in seismic design. An experimental program was carried out to evaluate the behavioral characteristics and performance of steel-reinforced, laminated elastomeric bearings, which had not been designed for seismic demands, as the primary quasi-isolation components for seismic events by permitting slip at the interface of the bearing and substructure. The rubber at the top of the bearing is vulcanized to a steel plate, which is bolted to the test frame to simulate a connection to the superstructure. At the base of the bearing, the elastomer directly contacts concrete representing the substructure, with no restraint of horizontal motion other than friction. The elastomeric bearings investigated during the experimental program displayed an approximately linear elastic response before sliding, with an initial friction coefficient in the range of 0.25–0.5 (at a shear strain between 125 and 250%) depending on combinations of the contact surface roughness, applied load, and bearing velocity. The friction coefficient decreased as a nonlinear function of the imposed vertical load. The maximum elastomer shear strain prior to sliding exhibited nonlinear increases with vertical load, resulting from the influence of the variable friction coefficient. Linear shear moduli were primarily influenced by the maximum shear strain imposed on the bearing, and showed shear stiffness reductions of approximately 40–50% following multiple, large displacement slip cycles, compared with 15–25% after reaching 50% shear strain. Multiple cycles of large displacement demands resulted in noticeable degradation in the friction coefficient over the duration of the tests. However, the bearings possessed a high degree of resiliency, considering that the specimens retained load-carrying capacity through total cumulative slip travel demands in the range of 3.5–4.5 m (140–180 in.).
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Acknowledgments
This paper is based on the results of ICT R27-70, Calibration and Refinement of Illinois’ Earthquake Resisting System Bridge Design Methodology (LaFave et al. 2013). ICT R27-70 was conducted in cooperation with the Illinois Center for Transportation (ICT), IDOT, Division of Highways, and the U.S. Department of Transportation, Federal Highway Administration (FHwA). The content of this paper reflects the view of the authors, who are responsible for the facts and the accuracy of the data presented herein. The content does not necessarily reflect the official views or policies of the ICT, IDOT, or FHwA. The authors would like to thank the members of the project Technical Review Panel, chaired by D. H. Tobias of the Illinois Department of Transportation, for their valuable assistance with this research.
References
AASHTO. (2008a). AASHTO LRFD bridge design specifications, AASHTO, Washington, DC.
AASHTO. (2008b). “Standard specification for plain and laminated elastomeric bridge bearings.” AASHTO M251-06, Washington, DC.
AASHTO. (2010). Guide specifications for seismic isolation design, AASHTO, Washington, DC.
ASTM. (2007). “Standard specification for plain and steel-laminated elastomeric bearings for bridges.” D4014-03, West Conshohocken, PA.
Buckle, I. G., and Mayes, R. L. (1990). “Seismic isolation: History, application, and performance—A world view.” Earthquake Spectra, 6(2), 161–201.
Buckle, I., Nagarajaiah, S., and Ferrell, K. (2002). “Stability of elastomeric isolation bearings: Experimental study.” J. Struct. Eng., 128(1), 3–11.
Calvi, G. M., and Pavese, A. (1997). “Conceptual design of isolation systems for bridge structures.” J. Earthquake Eng., 1(1), 193–218.
Filipov, E. T., et al. (2013a). “Seismic performance of highway bridges with fusing bearing components for quasi-isolation.” Earthquake Engineering and Structural Dynamics, in press.
Filipov, E. T., Fahnestock, L. A., Steelman, J. S., Hajjar, J. F., LaFave, J. M., and Foutch, D. A. (2013b). “Evaluation of quasi-isolated seismic bridge behavior using nonlinear bearing models.” Eng. Struct., 49(14), 168–181.
Filipov, E. T., Hajjar, J. F., Steelman, J. S., Fahnestock, L. A., LaFave, J. M., and Foutch, D. A. (2011). “Computational analyses of quasi-isolated bridges with fusing bearing components.” Proc., ASCE/SEI Structures Congress, ASCE, Reston, VA, 276–288.
Guo, K.-h., Zhuang, Y., Chen, S.-k., and William, L. (2006). “Experimental research on friction of vehicle tire rubber.” Front. Mech. Eng. China, 1(1), 14–20.
Highway Innovative Technology Evaluation Center (HITEC). (1996). Guidelines for the testing of seismic isolation and energy dissipating devices, ASCE, Reston, VA.
Illinois Department of Transportation (IDOT). (2007). Standard specification for road and bridge construction, IDOT, Springfield, IL.
Illinois Department of Transportation (IDOT). (2009). Bridge manual, IDOT, Springfield, IL.
International Concrete Repair Institute (ICRI). (1997). “Concrete surface profile chips.” 〈http://www.icri.org//bookstore/launchCatalog.asp?ItemID=PC〉 (Apr. 14, 2010).
Kelly, J. M., and Konstantinidis, D. (2009). “Effect of friction on unbonded elastomeric bearings.” J. Eng. Mech., 135(9), 953–960.
Kelly, J. M., and Konstantinidis, D. A. (2011). Mechanics of rubber bearings for seismic and vibration isolation, Wiley, Chichester, U.K.
Kikuchi, M., and Aiken, I. D. (1997). “An analytical hysteresis model for elastomeric seismic isolation bearings.” Earthquake Eng. Struct. Dyn., 26(2), 215–231.
Konstantinidis, D., Kelly, J. M., and Makris, N. (2008). “Experimental investigations on the seismic response of bridge bearings.” Rep. No. EERC 2008-02, Earthquake Engineering Research Center, College of Engineering, Univ. of California at Berkeley, Berkeley, CA.
Kulak, R. F., and Hughes, T. H. (1992). “Mechanical tests for validation of seismic isolation elastomer constitutive models.” Proc., Pressure Vessels and Piping Conf. on DOE Facilities Programs, Systems Interaction, and Active/Inactive Damping, C.-W. Lin and W. W. Chen, eds., Vol. 229, ASME, New York, 41–46.
LaFave, J., et al. (2013). “Experimental investigation of the seismic response of bridge bearings.” Research Report No. ICT-13-002, Illinois Center for Transportation, Univ. of Illinois at Urbana-Champaign, Urbana, IL.
Malaysian Rubber Producers’ Research Association (MRPRA). (1980). “Natural rubber engineering data sheet.” EDS 16, Malaysian Rubber Research and Development Board Organization, Hertford, U.K.
Mayes, R. L., and Naeim, F. (2001). “Design of structures with seismic isolation.” The seismic design handbook, F. Naeim, ed., Kluwer, Boston, 724–755.
McDonald, J., Heymsfield, E., and Avent, R. R. (2000). “Slippage of neoprene bridge bearings.” J. Bridge Eng., 5(3), 216–223.
Mori, A., Moss, P. J., Cooke, N., and Carr, A. J. (1999). “The behavior of bearings used for seismic isolation under shear and axial load.” Earthquake Spectra, 15(2), 199–224.
Muscarella, J. V., and Yura, J. A. (1995). “An experimental study of elastomeric bridge bearings with design recommendations.” Research Rep. No. 1304-3, Center for Transportation Research, Bureau of Engineering Research, Univ. of Texas at Austin, Austin, TX.
Persson, B. N. J. (2001). “Theory of rubber friction and contact mechanics.” J. Chem. Phys., 115(8), 3840–3861.
Roeder, C. W., Stanton, J. F., and Taylor, A. W. (1987). “Performance of elastomeric bearings.” National Cooperative Highway Research Program 298, Transportation Research Board, Washington, DC.
Schrage, I. (1981). “Anchoring of bearings by friction.” Special Publication SP70-12, American Concrete Institute, Detroit, 197–215.
Serway, A. R., and Beichner, R. J. (2000). Physics for scientists and engineers, Saunders College Publishing, Philadelphia.
Shenton, H. W. (1996). “Guidelines for pre-qualification, prototype and quality control testing of seismic isolation systems.” NISTIR 5800, NIST, Gaithersburg, MD.
Stanton, J. F., and Roeder, C. W. (1982). “Elastomeric bearings design, construction, and materials.” National Cooperative Highway Research Program 248, Transportation Research Board, National Research Council, Washington, DC.
Taylor, A. W., and Igusa, T. (2004). Primer on seismic isolation, ASCE, Reston, VA.
Tobias, D. H., Anderson, R. E., Hodel, C. E., Kramer, W. M., Wahab, R. M., and Chaput, R. J. (2008). “Overview of earthquake resisting system design and retrofit strategy for bridges in Illinois.” Pract. Period. Struct. Des. Constr., 13(3), 147–158.
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Published In
Journal of Bridge Engineering
Volume 18 • Issue 7 • July 2013
Pages: 612 - 623
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Aug 26, 2011
Accepted: Apr 24, 2012
Published online: Apr 26, 2012
Published in print: Jul 1, 2013
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