Seismic Performance of Degraded Shear Walls for Long-Term Compliance Periods
Luis Ibarra*, Biswajit Dasgupta**, and Kuang-Tsan Chiang**
*University of Utah, Department of Civil Engineering, 110 Central Campus Drive. Salt Lake City, UT 84112, USA
**Center for Nuclear Waste Regulatory Analyses, Southwest Research Institute®, 6220 Culebra Road, San Antonio, TX 78238, USA
Seismic performance evaluations of nuclear facilities are usually based on seismic probabilistic risk analyses that do not include the effects of concrete aging, which may decrease the capacity of reinforced concrete (RC) components with time. This study relates the physical mechanisms that take place during aging of concrete (e.g., cracking, and rebar corrosion) and the deterioration of mechanical properties that affect the system capacity under seismic events. The seismic performance evaluation uses available experimental data of steel reinforcement corrosion and variability of concrete parameters as a function of time. To obtain the variation in the system capacity caused by concrete aging, detailed numerical models of RC components and models of the selected structural systems are developed. The probability of unacceptable performance, or seismic failure, is computed by convolving the fragility data and selected hazard curves. The calculation includes the gain of concrete compressive strength with time. However, this gain in strength does not overcome the degradation of seismic performance caused by concrete cracking and corrosion of steel rebars. The results indicate that aging effects on RC components are largely influenced by seismic hazard at the site.
-  R. P. Kennedy and M. K. Ravindra, “Seismic Fragilities for Nuclear Power Plant Risk Studies,” Nuclear Engineering and Design, Vol.79. pp. 47-68, 1984.
-  J. I. Braverman, C. A. Miller, B. R. Ellingwood, D. J. Naus, C. H. Hofmayer, S. Shteyngart, and P. Bezler, NUREG/CR-6715, “Probability-Based Evaluation of Degraded Reinforced Concrete Components in Nuclear Power Plants,” Washington, DC: U.S. Nuclear Regulatory Commission, April 2001.
-  Y. Mori and B. R. Ellingwood, “Reliability-Based Service-Life Assessment of Aging Concrete Structures,” Journal of Structural Engineering, Vol.119, No.5. pp. 1600-1621, 1993.
-  K. Bhargava, Y. Mori, and A. K. Ghosh, “Time-dependent reliability of corrosion-affected RC beams – Parts 1-3,” Nuclear Engineering and Design, Vol.241, Issue 5, pp. 1371-1402, May 2011.
-  Computers and Structures, Inc., “Structural Analysis Program,” SAP2000, Version 14, Berkeley, California: Computer and Structures, Inc., 2009.
-  F. Barda, J. M. Hanson, and W. G. Corley, “Shear Strength of Low-Rise Walls With Boundary Elements. Reinforced Concrete Structures in Seismic Zones SP-53,” Detroit, Michigan: American Concrete Institute, pp. 149-202, 1977.
-  J. B. Mander, M. J. N. Priestley, and R. Park, “Theoretical Stress-Strain Model For Confined Concrete,” Vol.114, No.8, pp. 1804-1826, 1988.
-  American Society of Civil Engineers, “Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities,” ASCE/SEI 43-05, Reston, Virginia: American Society of Civil Engineers, 2005.
-  K. Chiang, L. Ibarra, and B. Dasgupta, “Effect of Temperature on the Compressive Strength of Concrete,” Transactions of SMiRT 21, Paper ID# 546, New Delhi, India, 2011.
-  G. D.Wyss and K. H. Jorgensen, “A User’s Guide to LHS: Sandia’s Latin Hypercube Sampling Software,” SAND98-0210, UC-505, Albuquerque, New Mexico: Sandia National Laboratories, February 1998.
-  L. F. Ibarra and H. Krawinkler, “Global Collapse of Frame Structures Under Seismic Excitations,” Pacific Earthquake Engineering Research (PEER), Report 2005/06, Berkeley, California: PEER Center, University of California, Berkeley, September 2005.
-  F. Jalayer, “Direct Probabilistic Seismic Analysis: Implementing Non-Linear Dynamic Assessment,” Ph.D. Dissertation, Department of Civil Engineering, Stanford University, California, 2003.
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