Using a performance-based earthquake engineering (PBEE) approach to estimate structural performance targets for bridges - Seismic Risk Analysis and Management of Civil Infrastructure Systems - page 550

standard deviations, etc.), statistical approach, and a well-constrained global
database were developed for California (Abrahamson et al. , 2008). In the
near future, new models will be developed for other tectonic environments
(e.g. subduction zones). The applicability of these new and improved global
GMPEs in PSHA studies of other regions is an important issue and should
be investigated by comparing the magnitude, distance, and site effects
scaling of these global models by regional datasets.
Recent studies (Baker and Cornell, 2005; Gülerce and Abrahamson,
2010) suggested that use of scalar-IMs may not be adequate in character-
izing the ground motion intensity and nonlinear structural response, thus
there is a need to develop vector-valued IMs and PSDMs. Integrating the
vector-valued PSDMs into the PSHA integral will require vector-valued
hazard computations, therefore standard PSHA software packages should
be modifi ed to develop the capability of performing vector-valued calcula-
tions. Also, the correlation of residuals of the ground motion model (or
models) across the periods should be provided by the developers of future
predictive models to be able to perform vector-valued probabilistic seismic
hazard and demand assessments. Finally, controversial issues such as selec-
tion and scaling of ground motions for nonlinear dynamic analysis and
functional shape of PSDMs are topics of ongoing discussions and require
further research efforts.
20.7 Acknowledgments
Funding for the UC Davis study was provided by the California Depart-
ment of Transportation (Caltrans) under Contract No. 59A0434 and is
gratefully acknowledged. The author is thankful to Dr Norman Abraham-
son, Dr Sashi K. Kunnath and Dr Emrah Erduran for their contribution to
the UC Davis study presented in this chapter.
20.8 References
Abrahamson, N. A., and Silva, W. J., 1997. Empirical response spectral attenuation
relations for shallow crustal earthquakes, Seismological Research Letters 68 ,
94-127.
Abrahamson, N. A., and Silva, W. J., 2008. Summary of the Abrahamson and Silva
NGA ground-motion relations, Earthquake Spectra 24 , 67-98.
Abrahamson, N. A., Atkinson, G., Boore, D., Bozorgnia, Y., Campbell, K., Chiou, B.,
Idriss, I. M., Silva, W. J., and Youngs, R., 2008. Comparisons of the NGA ground-
motion relations, Earthquake Spectra 24 , 45-66.
Baker, J., and Cornell, C. A., 2003. Uncertainty specifi cation and propagation for loss
estimation using FOSM method , Pacifi c Earthquake Engineering Research
Center, University of California, Berkeley, PEER 2003-07.