Probabilistic structural response assessment using vector-valued intensity measures

Methods for using scalar and vector ground motion intensity parameters to estimate the probabilistic relationship between ground motion intensity and structural response are described and compared. Options include using regression analysis on structural analysis results from a set of unsealed (or uniformly scaled) ground motions, or fitting a probability distribution to the analysis results from scaled ground motions analysed using incremental dynamic analysis and related methods. Past methods for using scalar ground motion intensity are reviewed, and methods for utilizing improved vector-valued intensity measures (IMs) are proposed. 'Hybrid' estimation methods that obtain the benefit of vector-valued IMs using simplified techniques such as careful record selection are also discussed. The results are then combined with models for ground motion occurrence obtained from probabilistic seismic hazard analysis to compute seismic reliability, and the results obtained from the various methods are compared. In general, a tradeoff must be made between the accuracy of the functional relationship between ground motion intensity and structural response versus the number of structural analyses needed for estimation. Copyright (C) 2007 John Wiley & Sons, Ltd.