Dynamic Lateral Stability of Elastomeric Seismic Isolation Bearings
Publication: Journal of Structural Engineering
Volume 140, Issue 8
Abstract
Predicting the response of elastomeric seismic isolation bearings when subjected to severe ground motions is challenging due to the highly nonlinear behavior associated with the bearings under a combination of large displacements and axial loads. In particular, the horizontal stiffness of the bearings is a function of both horizontal displacement as well as axial load that varies due to overturning moments. Previous analytical models or formulations to model these bearings were mainly developed to estimate critical loads at the stability limit. Only few of these models are capable of estimating the correct nonlinear behavior of bearings observed at horizontal displacements in excess of the bearing width. In this study, a nonlinear analytical model is presented that is capable of modeling the dynamic response of bearings more accurately at all displacement ranges, especially beyond the stability limit and is verified with experimental data from an earlier experimental study. It was observed in the dynamic experiments that the bearings have a far larger capability to sustain horizontal loads at displacements exceeding their stability limit than predicted by earlier models and more importantly the bearings re-centered after these large displacement excursions. This behavior is captured using the analytical model developed in this study.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Authors VSMV and SN gratefully acknowledge funding support provided by grant NSF-CMMI-NEESR-0830391 for this project. AM and GM were supported by NSF-NEESR-CMMI-1113275.
References
Bažant, Z. P. (2003). “Shear buckling of sandwich, fiber composite and lattice columns, bearings, and helical springs: Paradox resolved.” J. Appl. Mech., 70(1), 75–83.
Bažant, Z. P., and Cedolin, L. (1991). Stability of Structures, Oxford University Press, New York.
Buckle, I., and Kelly, J. M. (1986). “Properties of slender elastomeric isolation bearings during shake table studies of a large-scale model bridge deck.” Joint Sealing and bearing systems for concrete structures, Vol. 1, American Concrete Institute, Detroit, 247–269.
Buckle, I., Nagarajaiah, S., and Ferrell, K. (2002). “Stability of elastomeric isolation bearings: Experimental study.” J. Struct. Eng., 3–11.
Cardone, D., and Perrone, G. (2012). “Critical load of slender elastomeric seismic isolators: An experimental perspective.” Eng. Struct., 40, 198–204.
Derham, C. J., and Thomas, A. G. (1981). “The design of seismic isolation bearings.” Control of seismic response of piping system and other structures, Univ. of California, Berkeley, CA21–36.
Gent, A. N. (1964). “Elastic stability of rubber compression springs.” J. Mech. Eng. Sci., 6(4), 318–326.
Griffith, M. C., Kelly, J. M., and Aiken, I. D. (1987). “A displacement control and uplift restraint device for base isolated devices.”, Earthquake Engineering Research Center, Univ. of California, Berkeley, CA.
Han, X., Kelleher, C. A., Warn, G. P., and Wagener, T. (2013). “Identification of the controlling mechanism for predicting critical loads in elastomeric bearings.” J. Struct. Eng., 04013016.
Haringx, J. A. (1948). “On highly compressible helical springs and rubber rods and their application for vibration-free mountings. I.” Phillips Res. Rep., 3, 401–449.
Haringx, J. A. (1949a). “On highly compressible helical springs and rubber rods and their application for vibration-free mountings. II.” Phillips Res. Rep., 4, 49–80.
Haringx, J. A. (1949b). “On highly compressible helical springs and rubber rods and their application for vibration-free mountings. III.” Phillips Res. Rep., 4, 206–220.
Iizuka, M. (2000). “A macroscopic model for predicting large-deformation behaviors of laminated rubber bearings.” Eng. Struct., 22(4), 323–334.
Kikuchi, M., Nakamura, T., and Aiken, I. D. (2010). “Three-dimensional analysis for square seismic isolation bearings under large shear deformations and high axial loads.” Earthquake Eng. Struct. Dyn., 39(13), 1513–1531.
Koh, C. G., and Kelly, J. M. (1986). Effects of axial load on elastomeric bearings, Earthquake Engineering Research Center, Univ. of California, Berkeley, CA.
Koh, C. G., and Kelly, J. M. (1988). “A simple mechanical model for elastomeric bearings used in base isolation.” Int. J. Mech. Sci., 30(12), 933–943.
Koh, C. G., and Kelly, J. M. (1989). “Viscoelastic stability model for elastomeric isolation bearings.” J. Struct. Eng., 285–302.
Masroor, A., Sanchez, J., Mosqueda, G., and Ryan, K. L. (2012). “Dynamic stability of elastomeric bearings at large displacement.” Proc., 15th World Conf. on Earthquake Engineering, National Information Center of Earthquake Engineering, Kanpur, India.
Nagarajaiah, S., and Ferrell, K. (1999). “Stability of elastomeric seismic isolation bearings.” J. Struct. Eng., 946–954.
Nagarajaiah, S., Reinhorn, A. M., and Constantinou, M. C. (1991). “Nonlinear dynamic analysis of 3-d-base-isolated structures.” J. Struct. Eng., 2035–2054.
Sanchez, J. (2011). “Stability of elastomeric bearings for seismic applications.” M.S. thesis, Dept. of Civil, Structural and Environmental Engineering, Univ. of Buffalo, Buffalo, NY.
Sanchez, J., Masroor, A., Mosqueda, G., and Ryan, K. L. (2013). “Static and dynamic stability of elastomeric bearings for seismic protection of structures.” J. Struct. Eng., 1149–1159.
Warn, G. P., and Weisman, J. (2011). “Parametric finite element investigation of the critical load capacity of elastomeric strip bearings.” Eng. Struct., 33(12), 3509–3515.
Weisman, J., and Warn, G. P. (2012). “Stability of elastomeric and lead-rubber seismic isolation bearings.” J. Struct. Eng., 215–223.
Information & Authors
Information
Published In
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 5, 2013
Accepted: Sep 19, 2013
Published online: Apr 7, 2014
Published in print: Aug 1, 2014
Discussion open until: Sep 7, 2014
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.