New Simplified Method for Designing Seismically Isolated Highway Bridges with Massive Piers
Publication: Journal of Bridge Engineering
Volume 22, Issue 8
Abstract
This paper proposes two new models for the simplified seismic analysis of seismically isolated highway bridges with massive piers. Both models include two components, one of which includes the superstructure mass, the isolators, and massless pier, and the other one the pier with its distributed mass and stiffness properties. In one model, the isolator stiffness is added at the top of the pier in the second component. The total seismic response is obtained from the square root of the sum of squares (SRSS) of the two individual component results. Applicability and accuracy of the models were assessed by considering bridges with wide ranges of stiffness and mass properties of piers (Mp) and superstructures (Mss). Multimode spectral analysis (MMSA) and nonlinear time-history analysis (NLTHA) were used to define reference solutions for the superstructure displacements, vibration periods, and shears and moments at pier bases. Results from four currently available models, including the model prescribed in American and Canadian bridge codes, were also examined. The study shows that current models for the simplified analysis method yield good estimates of superstructure displacements and vibration periods; however, they generally underestimate the shear and moment demands at pier bases. The errors are more significant for more massive piers or when the stiffness of the piers is high compared to that of the isolators. In contrast, for all bridges studied, the seismic responses from the proposed models show very good agreement with those from the MMSA. Better predictions are obtained when considering the isolator stiffness in the second component of the model. The NLTHA results also show that the proposed models give overall satisfactory predictions for pier base shears and moments. The proposed models extend the range of application of the American and Canadian code simplified method to isolated bridges with massive piers while preserving its simplicity with limited extra computational effort.
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Acknowledgments
This research was supported by the Key Consulting Project of Chinese Academy of Engineering (Grant 2016-XZ-13). The authors acknowledge financial support from the China Scholarship Council (CSC) and the Natural Sciences and Engineering Research Council of Canada (NSERC).
References
AASHTO. (2014). Guide specifications for seismic isolation design, 4th Ed., Washington, DC.
Adhikari, G., Petrini, L., and Calvi, G. M. (2010). “Application of direct displacement based design to long span bridges.” Bull. Earthquake Eng., (8(4), 897–919.
Al-Ani, M., and Singh, C. (2014). “Influence of substructure properties on analysis and design of seismically-isolated bridges.” Proc., 9th Austroads Bridge Conf., ARRB Group and Authors, Sydney, New South Wales, Australia.
ATC (Applied Technology Council). (1996). Seismic evaluation and retrofit of concrete buildings, Redwood City, CA.
Buckle, I. G., Al-Ani, M., and Monzon, E. (2011). “Seismic isolation design examples for highway bridges.” Technical Rep. No. NCHRP Project 20-7-Task 262, National Cooperative Highway Research Program, Washington, DC.
Buckle, I. G., Constantinou, M., Dicleli, M., and Ghasemi, H. (2006). “Seismic isolation of highway bridges.” Technical Rep. No. MCEER-06-SP07, State Univ. of New York at Buffalo, Buffalo, NY.
Cardone, D., Dolce, M., and Palermo, G. (2009). “Evaluation of simplified methods for the design of bridges with seismic isolation systems.” Earthquake Spectra, 25(2), 221–238.
Constantinou, M. C., Kalpakidis, I., Filiatrault, A., and Ecker Lay, R. A. (2011). “LRFD-based analysis and design procedures for bridge bearings and seismic isolators.” Technical Rep. No. MCEER-11-0004, State Univ. of New York at Buffalo, Buffalo, NY.
CSA (Canadian Standards Association). (2014). “Canadian highway bridge design code,” CAN/CSA S6-14, Rexdale, Toronto.
CSI (Computers and Structures Inc.). (2014). SAP2000: Integrated finite element analysis and design of structures basic analysis reference manual, Berkeley CA.
Dicleli, M., and Mansour, M. (2003). “Seismic retrofitting of highway bridges in Illinois using friction pendulum seismic isolation bearings and modeling procedures.” Eng. Struct., 25(9), 1139–1156.
Dicleli, M., Mansour, M. Y., and Constantinou, M. C. (2005). “Efficiency of seismic isolation for seismic retrofitting of heavy substructured bridges.” J. Bridge Eng., 429–441.
Earthquake Protection Systems, Inc. (1999). Friction pendulum seismic isolation bearing: Details and specifications for bridges, Richmond, CA.
Fadi, F., and Constantinou, M. C. (2010). “Evaluation of simplified methods of analysis for structures with triple friction pendulum isolators.” Earthquake Eng. Struct. Dyn., 39(1), 5–22.
Feng, M. Q., and Lee, S. C. (2009). “Determining the effective system damping of highway bridges.” Rep. No. CA-UCI-2009-00, Univ. of California, Irvine, CA.
FHWA (Federal Highway Administration). (2014). “LRFD seismic analysis and design of bridges reference manual.” FHWA-NHI-15-004, U.S. Dept. of Transportation, Washington, DC.
Franchin, P., Monti, G., and Pinto, P. E. (2001). “On the accuracy of simplified methods for the analysis of isolated bridges.” Earthquake Eng. Struct. Dyn., 30(3), 363–382.
Guyader, A. C., and Iwan, W. D. (2006). “Determining equivalent linear parameters for use in a capacity spectrum method of analysis.” J. Struct. Eng., 59–67.
Hwang, J. S., Chang, K. C., and Tsai, M. H. (1997). “Composite damping ratio of seismically isolated regular bridges.” Eng. Struct., 19(1), 55–62.
Jara, M., and Casas, J. R. (2006). “A direct displacement-based method for the seismic design of bridges on bi-linear isolation devices.” Eng. Struct., 28(6), 869–879.
Jara, M., Jara, J. M., Olmos, B. A., and Casas, J. R. (2012). “Improved procedure for equivalent linearization of bridges supported on hysteretic isolators.” Eng. Struct., 35, 99–106.
Karnovsky, I. A., and Lebed, O. I. (2000). Formulas for structural dynamics: Tables, graphs and solutions, McGraw Hill, New York.
Leroux, M. (2015). “Seismic isolation: A study of inertial forces in bridge’s piers.” Master of engineering thesis, Ecole Polytechnique de Montreal, Quebec, Canada (in French).
Ozdemir, G., and Constantinou, M. C. (2010). “Evaluation of equivalent lateral force procedure in estimating seismic isolator displacements.” Soil Dyn. Earthquake Eng., 30(10), 1036–1042.
Priestley, M. J. N., Seible, F., and Calvi, G. M. (1996). Seismic design and retrofit of bridges, Wiley, New York.
Reinhorn, A. M., Simeonov, V. K., DeRue, G., and Constantinou, M. C. (1998). “Sensitivity of response of isolated bridges to modeling and design parameters: A case study.” Technical Rep. No. 98-0015, Columbia Univ., New York, 213–223.
SAP2000 [Computer software]. Computers and Structures, Inc., Berkeley CA.
Tsopelas, P., Constantinou, M. C., Kircher, C. A., and Whittaker, A. S. (1997). “Evaluation of simplified methods of analysis for yielding structures.” Technical Rep. No. NCEER-97-0012, State Univ. of New York at Buffalo, Buffalo, NY.
Wei, C., and Buckle, I. G. (2012). “A simplified method of analysis of isolated bridges with yielding substructures.” Proc., Structures Congress, ASCE, Reston, VA, 559–570.
Wei, C., Al-Ani, M., and Buckle, I. G. (2013). “An improved simplified method for the analysis of seismically isolated highway bridge with heavy substructure.” Proc., 7th National Seismic Conf. on Bridges and Highways, 1–7.
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Published In
Journal of Bridge Engineering
Volume 22 • Issue 8 • August 2017
Copyright
© 2017 American Society of Civil Engineers.
History
Received: Aug 29, 2016
Accepted: Mar 15, 2017
Published online: May 31, 2017
Published in print: Aug 1, 2017
Discussion open until: Oct 31, 2017
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