The ability of available, performance-based, analytical methods to predict reliably the performance of building structural systems in a major earthquake (mainshocks) and subsequent triggered aftershocks, (or other cascading hazard events) concerns earthquake engineering research. The possible damage to structures from cascading, shallow-focused, seismic events was provoked by the collapse of the CTV Building in the 22 February 2011, the Canterbury (Christchurch) region of New Zealand earthquake (Mw=6.3). That earthquake had followed the 4 September, 2010 Darfield earthquake (Mw=7.1) in the same region and a series of fairly strong aftershocks. (See: Forsyth Barr/CTV Building hearing:
Expert Panel Report: Structural Performance of Christchurch CBD Buildings in 22 February 2011 Aftershock.)
Analytically derived performance predictions (including “blind prediction competitions”) have achieved only mixed success with full scale experimental seismic testing results, — for example in Japan’s E-defense full-scale shaking table testing of steel moment frames –
Lignos, D.G., Hikino, T., Matsuoka, Y., and Nakashima, M., “Collapse assessment of steel moment frames based on E-Defense full-scale shake table collapse tests”, Journal of Structural Engineering, ASCE, 139:120-132; (2013)
Maison, B., Kasai, K., and Deierlein, G. “Study of building collapse for performance-based design validation.” Structures Congress 2008: Crossing Borders. pp. 1-10 (ASCE : 2008);
Lignos, D.G. (2012). “Modeling and experimental validation of a full scale 5-story steel building equipped with triple friction pendulum bearings: E-Defense blind analysis competition,” Proceedings 9th, International Conference on Urban Earthquake Engineering (9CUEE) & 4th Asia Conference on Earthquake Engineering, Tokyo, Japan; March 6-8, 2012.
Using reduced-scale models in shaking table testing at the University at Buffalo for validation, analytical performance predictions for four-story steel moment frames provided guarded success —
Lignos, D.G., Krawinkler, H., Whittaker, A.S. “Contributions to collapse prediction of steel moment frames through recent earthquake simulator collapse tests.” 3rd International Conference on Advances in Experimental Structural Engineering, October 15-16, 2009. San Francisco. (October, 2009).
A recent blind prediction competition using shake table testing of a full-scale, reinforced concrete bridge column subjected to six consecutive unidirectional ground motions at U.C. San Diego test facilities produced a wide variance in validity of performance predictions. —
Terzic, V., Schoettler, M., and Mahin, S.A. “Uncertainty in modeling seismic response of reinforced concrete bridge columns.” 9th International Conference on Urban Earthquake Engineering/ 4th Asia Conference on Earthquake Engineering, Tokyo Institute of Technology, Tokyo, Japan (2012).
For taller buildings (at least 160 feet in height), too large for reasonable laboratory shake table testing, the PEER/ATC-72-1 report : (Malley, J. et al) “Modeling and acceptance criteria … “ (2010), provides a near, ‘state-of-the-art’ compendium of recent available research, information, and recommendations on analytical modeling and acceptance criteria for the design and analysis of tall structural systems. Some methodologies for damage assessment of mid-rise building structural systems under cascading seismic events have also been elaborated in a variety of research studies — See for example:
Luco, N., Gerstenberger, M.C., Uma, S., Ryu, H., Liel, A.B., and Raghunandan, M. “A methodology for post-mainshock probabilistic assessment of building collapse risk.” Pacific Conference on Earthquake Engineering, Auckland, New Zealand (April, 2011).
Lee, K. and Foutch, D. “Performance evaluation of damaged steel frame buildings subjected to seismic loads.” Journal of Structural Engineering (ASCE), 130(4), 588–599. (April, 2004);
Li, Q. and Ellingwood, B.R. “Performance evaluation and damage assessment of steel frame buildings under main shock-aftershock earthquake sequences.” Earthquake Engineering & Structural Dynamics, 36(3), 405–427. (March, 2007).
M. Raghunandan, Liel, A.B.,Ryu, H., Luco, N., Uma, S.R. “Aftershock fragility curves and tagging assessments for a mainshock-damaged building.” Proceedings of the 15th World Conference in Earthquake Engineering (15WCEE), September 24-28, Lisbon, Portugal, 2012.
Eads, L., Miranda, E., Krawinkler, H., Lignos, D.G., (2012). “Improved estimation of collapse risk for structures in seismic regions,” Proceedings of the 15th World Conference of Earthquake Engineering (15WCEE), September 24-28, Lisbon, Portugal, 2012.
The complex challenges in accurately modeling the expected mainshock and aftershock seismic sequences for use in structural and non-structural damage analytical assessment prediction are recognized in recent work including –
Baker, J.W. “Probabilistic structural response assessment using vector-valued intensity measures.” Earthquake Engineering & Structural Dynamics, 36(13), 1861–1883; (9 May, 2007).
Ruiz-García, J. “Mainshock-aftershock ground motion features and their influence in building’s seismic response.” Journal of Earthquake Engineering, 16(5), 719-737; (26 June, 2012).
Work on improved analytical methods for reliable prediction of structural systems performance under realistic, cascading seismic events continues widely.