Document Type




Format of Original

19 p.

Publication Date




Source Publication

Earthquake Engineering & Structural Dynamics

Source ISSN


Original Item ID

DOI: 10.1002/eqe.2301


The conditional spectrum (CS, with mean and variability) is a target response spectrum that links nonlinear dynamic analysis back to probabilistic seismic hazard analysis for ground motion selection. The CS is computed on the basis of a specified conditioning period, whereas structures under consideration may be sensitive to response spectral amplitudes at multiple periods of excitation. Questions remain regarding the appropriate choice of conditioning period when utilizing the CS as the target spectrum. This paper focuses on risk-based assessments, which estimate the annual rate of exceeding a specified structural response amplitude. Seismic hazard analysis, ground motion selection, and nonlinear dynamic analysis are performed, using the conditional spectra with varying conditioning periods, to assess the performance of a 20-story reinforced concrete frame structure. It is shown here that risk-based assessments are relatively insensitive to the choice of conditioning period when the ground motions are carefully selected to ensure hazard consistency. This observed insensitivity to the conditioning period comes from the fact that, when CS-based ground motion selection is used, the distributions of response spectra of the selected ground motions are consistent with the site ground motion hazard curves at all relevant periods; this consistency with the site hazard curves is independent of the conditioning period. The importance of an exact CS (which incorporates multiple causal earthquakes and ground motion prediction models) to achieve the appropriate spectral variability at periods away from the conditioning period is also highlighted. The findings of this paper are expected theoretically but have not been empirically demonstrated previously.


Accepted version. Earthquake Engineering & Structural Dynamics, Vol. 42, No. 12 (October 10, 2013): 1847-1865. DOI. © 2013 John Wiley & Sons, Ltd. Used with permission.

This is the peer reviewed version of the following article: Earthquake Engineering & Structural Dynamics, Vol. 42, No. 12 (October 10, 2013): 1847-1865, which has been published in final form at [DOI. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

Ting Lin was affiliated with Stanford University at the time of publication.